FAQ
Answers to frequently asked questions about construction materials
How much adhesive do I need per square meter of tiles?
For standard tiles (up to 60x60 cm) you need about 5 kg of adhesive per m². For large-format tiles (over 60x60 cm) you need 6-7 kg/m² because the adhesive must transfer better.
How do I calculate the number of tiles needed, including an allowance?
We recommend an allowance of 5-15% depending on the complexity of the layout: 5% for simple straight laying, 10% for diagonal, 15% for complex patterns or rooms with many corners.
What is the optimal grout joint width for ceramic tiles?
The standard joint width is 2-3 mm for indoor spaces. For outdoor spaces 5-8 mm is recommended because of thermal expansion. Large-format tiles require a joint of at least 2 mm.
How much grout do I need for my tiles?
The amount of grout depends on tile size and joint width. For 60x60 cm tiles with a 2 mm joint you will need about 0.5 kg/m². Our calculator works out the exact amount automatically.
Can I use the same tiles for the floor and the wall?
Yes, but pay attention to the slip-resistance class. Floor tiles should have an R9-R11 rating for indoor spaces, while wall tiles have no such requirement.
What is the difference between rectified and non-rectified tiles?
Rectified tiles have precisely cut edges at right angles, which allows laying with a minimal joint (1-2 mm). Non-rectified tiles have rounded edges and require a wider joint.
How do I choose the right tile adhesive?
For indoor spaces a standard flexible C2TE adhesive is enough. For outdoor areas, pools or underfloor heating use class S1 or S2. For large-format tiles C2TES1 is mandatory.
How many tiles come in one box?
It depends on size. For 60x60 cm usually 4 pcs (1.44 m²), for 30x30 cm about 11 pcs (1 m²). Check the manufacturer's specifications as they may differ.
Is it necessary to seal the grout?
Yes, especially in damp rooms (bathrooms, kitchens). Sealing protects against moisture and mold and makes cleaning easier. It is applied 24-48 hours after grouting.
How do I prepare the substrate for tiling?
The substrate must be clean, dry, level and load-bearing. Unevenness greater than 3 mm over 2 m must be leveled. Use primer on absorbent substrates and a bonding coat on non-absorbent ones.
What are leveling systems and what are they for?
Leveling systems align tiles while they are being laid. They consist of clips that stay in the floor and wedges that are reused. They ensure a flat surface with no lippage between tiles.
How many leveling clips do I need per square meter?
It depends on tile size: 20-30 cm = 16 pcs/m², 60-80 cm = 4 pcs/m², 100-120 cm = 2.5 pcs/m². Larger tiles need fewer clips.
Can I reuse the leveling clips?
The clips are single-use and stay in the floor. The wedges are reusable and can be used on multiple projects - usually 50-100 times.
Which leveler thickness is best?
The most common are 1.5 mm or 2 mm. For rectified tiles with a minimal joint use 1 mm. For rustic tiles or wider joints use 2-3 mm.
When should I remove the levelers after laying?
Remove the wedges after 24-48 hours, depending on temperature and humidity. The adhesive must be sufficiently dry. Break off the clips with a tap of a rubber mallet parallel to the joint.
Are leveling systems mandatory?
They are not mandatory, but they make it much easier to get a flat surface, especially with large-format tiles. They reduce the need for later grinding and correction.
How do I place the levelers correctly?
Place the clip at the junction of four tiles and push in the wedge until the tiles are flush. Do not press too hard, as you may damage the tiles or the substrate.
Are there different types of leveling systems?
Yes, the most common are the wedge system (economical), the tension system (faster work) and the rotary system (highest precision). Choose according to project size and budget.
Can I use levelers on a wall?
Yes, especially with large-format tiles. Use a faster-setting adhesive and additionally secure the tiles until the adhesive hardens.
How many wedges do I need relative to the clips?
Usually 1 wedge per 3 clips, because wedges are reused. Our calculator works out the optimal ratio automatically.
How much putty do I need per m²?
On flat, prepared walls two thin coats are enough, for which the calculator uses 1.5 kg/m² in total. Uneven and very absorbent walls use more, and thicker unevenness should first be levelled with another material.
How much paint do I need per m²?
The calculator uses 0.125 L/m² per coat, i.e. 0.25 L/m² for the recommended two coats. Rough and absorbent surfaces and dark shades use more; see the paint’s technical data sheet.
How many coats of paint should I apply?
At least two coats for optimal coverage. When going from a dark to a light color you may need 3-4 coats or the use of a primer.
Do I need to prime before painting?
Yes, priming improves paint adhesion, evens out the absorbency of the substrate and reduces the consumption of the topcoat. It is especially important on new or highly absorbent substrates.
How do I calculate wall area with deductions for windows and doors?
Calculate the total wall area (perimeter × height), then subtract the area of windows and doors. Our calculator does this automatically.
What is the difference between putty for wet and dry rooms?
Putty for wet rooms (bathrooms, kitchens) is waterproof and mold-resistant. For dry rooms standard putty can be used.
How long does putty take to dry?
Depending on layer thickness and conditions: a thin layer 4-6 hours, a thicker layer 12-24 hours. Wait at least 24 hours before sanding.
Do I need to sand between coats of paint?
Usually not necessary for dispersion paints. Light sanding with fine paper (P180-P220) is recommended only if there are drips or impurities.
How do I calculate the ceiling area?
Multiply the length and width of the room. For irregularly shaped rooms, divide into rectangular parts and add up the areas.
What type of paint is best for interior walls?
For living areas, a class 1-2 dispersion paint. For bathrooms and kitchens, a latex or special moisture-resistant paint. For children's rooms, a paint free of harmful emissions.
What is an ETICS system?
ETICS (External Thermal Insulation Composite System) is a thermal insulation system that includes adhesive, insulation material, anchors, reinforcing mesh and finishing render.
How much adhesive do I need to bond polystyrene?
On average 5-6 kg/m² when applied with the ribbon-and-dab method. For full-surface application on flat substrates you need 4-5 kg/m².
What polystyrene thickness is optimal?
For energy efficiency, at least 12-15 cm of EPS or 10-12 cm of rock wool is recommended. Check the requirements under the energy efficiency law.
How much reinforcing mesh do I need?
Count 1.1 m² of mesh per m² of facade because of overlap (min. 10 cm). For corners and openings add diagonal strips.
How much finishing render do I need?
It depends on grain size: for 1.5 mm about 2.2 kg/m², for 2 mm about 2.8 kg/m², for 3 mm about 4 kg/m². Actual consumption also depends on the application technique.
Which profiles are needed for a facade?
Starter (plinth) profiles along the bottom edge, corner profiles on external corners and reveal edges, window connection profiles along the frame and drip profiles above openings. The calculator works them out from the edges and openings you mark on the drawing.
Can I do a facade in winter?
Work at temperatures below +5°C is not recommended. Adhesives and renders need suitable temperatures to dry and set properly.
How long does it take to complete a facade?
For a house with 150 m² of facade allow 2-3 weeks depending on weather conditions. Each layer must dry before the next one is applied.
What is the difference between EPS and rock wool?
EPS is lighter and cheaper, while stone wool is non-combustible and better at damping sound. For taller buildings and fire barriers regulations often require a non-combustible material – check your country's rules and the system requirements.
How do I choose the facade anchor length?
Anchor length = insulation thickness + at least 40 mm of anchorage into the wall. For 10 cm of polystyrene use anchors of at least 140 mm.
What is the difference between plastic and metal anchors?
Plastic anchors are more economical and prevent thermal bridges. Metal ones have a higher load capacity and are used for heavier cladding materials or poorer substrates.
How do I arrange the anchors on a facade correctly?
Most often a W or T pattern: anchors at the panel corners and one in the middle. Add extra anchors for edge zones. Our calculator shows a visual diagram of the pattern.
Do I need more anchors at the corners of a building?
Yes, edge zones require a higher density - 8-10 pcs/m² instead of the standard 4-6 pcs/m². The edge zone is usually 1-1.5 m from all corners and openings.
Can I fix the anchors through the reinforcing layer?
Yes, this is even recommended because it gives a better bond for the whole system. The anchor is set after applying the reinforcing layer while it is still fresh.
How many anchors come in a pack?
The standard pack is 100 pieces. For larger projects packs of 200 or 500 pieces are also available at a better price.
What are the advantages of anchors with a plastic pin?
They eliminate thermal bridges, do not corrode and are easier to install. The drawback is lower load capacity compared with metal pins.
How far from the panel edge do I place an anchor?
At least 5 cm from the panel edge and at least 10 cm from the edge of the wall or opening. Anchors are placed at the junctions of four panels.
How do I drill the anchor holes correctly?
Use a hammer drill and a bit of the right diameter (usually 8-10 mm). Hole depth = anchor length - insulation thickness.
What should I do if an anchor does not hold well?
Check the load-bearing capacity of the substrate, use a longer anchor or switch to an anchor with a metal pin. For weak substrates there are special injection anchors.
How do I calculate the wall area?
Wall area = width × height. For a room with 4 walls add up all the individual areas. Subtract windows and doors from the total to get the net area.
What is the difference between gross and net area?
Gross area is the total wall area without deductions. Net area is the gross area minus openings (windows, doors). Use the net area when calculating materials.
How do I calculate the surface area of geometric solids?
The calculator works out the area of plane figures (rectangle, circle, triangle, trapezoid; a triangle also from its three sides with Heron's formula) and the surface area of 12 solids (rectangular prism, cube, cylinder, sphere, cone, prism, pyramid, truncated cone, truncated pyramid, ellipsoid, torus, spherical segment). It shows the formula for each shape and adds everything to the overall total.
What is the lateral surface area?
The lateral surface area is the area of the sides of a solid only, without the bases. For a cylinder, for example, it is only the curved surface (2πrh), while the total surface area also includes both circles.
How do I calculate the surface area of an ellipsoid?
There is no exact formula for an ellipsoid. Our calculator uses the Knud Thomsen approximation, which gives results with an error of less than 1.061%.
Which unit of measurement is best for entering dimensions?
For construction work meters are most commonly used. For smaller objects, centimeters or millimeters. The calculator automatically converts results into all three units.
How do I calculate the surface area of a torus?
Torus surface area = 4π²Rr, where R is the distance from the center and r is the radius of the cross-section. A torus is a shape like a tire or a doughnut.
What is a spherical segment?
A spherical segment is a part of a sphere cut off by a plane. Segment area = 2πRh, where R is the sphere radius and h is the segment height. It may also include the circular base.
How do I calculate the surface area of a truncated cone?
A truncated cone has two radii (R and r). Lateral area = π(R+r)l, where l is the slant height. The total area also includes both base circles.
Can I save area calculations?
Yes, after calculating you can save the results to history or a project. You can also export a PDF with the calculation details.
How do I calculate the volume of a rectangular box (cuboid)?
Volume of a cuboid = length × width × height (V = a × b × c). For a cube the formula is simpler: V = a³.
What is the difference between a prism and a pyramid?
A prism has two identical bases connected by rectangular sides. A pyramid has one base and side faces that meet at an apex. The volume of a pyramid is 1/3 of the volume of a prism with the same base and height.
How do I calculate the volume of a cylinder?
Volume of a cylinder = π × r² × h, where r is the base radius and h is the height. For example, for a cylinder with a radius of 10 cm and a height of 20 cm: V = 3.14159 × 100 × 20 = 6283.2 cm³.
How do I calculate the volume of a sphere?
Volume of a sphere = (4/3) × π × r³. For example, a sphere with a radius of 10 cm has a volume of approximately 4188.8 cm³.
What is a truncated cone and how do I calculate its volume?
A truncated cone is a cone with its top cut off. Volume = (1/3)πh(R² + Rr + r²), where R and r are the base radii and h is the height.
How do I calculate the volume of an ellipsoid?
Volume of an ellipsoid = (4/3)π × a × b × c, where a, b and c are the semi-axes. If all three are equal, we get a sphere.
What is a torus and how do I calculate its volume?
A torus is a shape like a tire or a doughnut. Volume = 2π²Rr², where R is the distance from the center of the torus to the axis and r is the radius of the tube cross-section.
What is a volume calculator useful for in construction?
It is used to calculate concrete for foundations, tank volumes, the amount of fill material needed, capacities of cisterns and pools, and excavation volumes.
How do I calculate the volume of an irregular shape?
Divide the irregular shape into simpler shapes (rectangles, cylinders, cones) and add up their volumes. Our calculator lets you add multiple shapes.
Can I convert the results into liters?
Yes, 1 dm³ = 1 liter. Divide a result in cm³ by 1000 to get liters, or multiply m³ by 1000 to get liters.
What is self-leveling compound and what is it used for?
Self-leveling compound is a self-leveling mass used to level floors before laying the final covering (tiles, laminate, parquet). It is used to correct unevenness of up to 10 mm.
How much self-leveling compound is needed per square meter?
Consumption depends on layer thickness. The standard is 1.7 kg/m² for each millimeter of thickness. For a 5 mm layer you need about 8.5 kg/m².
What are the minimum and maximum thickness of self-leveling compound?
The minimum thickness is usually 2-3 mm, and the maximum is 10 mm in one layer. For larger unevenness it must be applied in several layers.
Is a primer needed before self-leveling compound?
Yes, applying a primer is recommended to improve adhesion and prevent the substrate from absorbing water from the compound too quickly.
How quickly does self-leveling compound dry?
Walking is possible after 3-4 hours, but you should wait 24-48 hours before laying the covering, depending on layer thickness and room humidity.
How many blocks are needed for masonry?
The number of blocks depends on the dimensions of the block and the wall. Our calculator automatically calculates the required number of blocks, including joints and a reserve for cutting.
What is the difference between mortar, thin-bed adhesive and PUR foam?
Mortar is used for standard brick and concrete blocks (10 mm joint). Thin-bed adhesive is for aerated concrete (2-3 mm joint). PUR foam is the fastest method for aerated concrete.
How much mortar is needed for masonry?
Mortar consumption depends on block size and joint width. For standard brick with a 10 mm joint, count about 25-30 kg/m² of wall.
What is aerated concrete (AAC)?
Aerated concrete is a lightweight building material with good thermal properties. It is laid with thin-bed adhesive or PUR foam. It is lighter than standard brick.
How do I calculate the area of openings for windows and doors?
In the calculator you can add openings by entering the width and height of each opening. The opening area is automatically deducted from the total wall area.
Can I save my own block dimensions?
Yes, signed-in users can save custom block templates with their own dimensions and select compatible laying methods.
How much concrete do I need for a slab?
Concrete volume = length × width × thickness. For a 5×4 m slab 15 cm thick you need 3 m³ of concrete. We recommend a 5-10% reserve.
What is the difference between hand-mixed and ready-mixed concrete?
Ready-mixed concrete from a batching plant is more consistent and more economical for larger quantities. Hand mixing is more practical for smaller projects up to 1-2 m³.
How much aggregate do I need for hand-mixing concrete?
For 1 m³ of M25 concrete you need about 350 kg of cement, 1800 kg of aggregate (sand + gravel) and about 175 liters of water. Our calculator computes the exact quantities.
What is a concrete class (e.g. C25/30)?
The concrete class indicates compressive strength in N/mm². C25/30 means a characteristic strength of 25 N/mm² on a cylinder and 30 N/mm² on a cube after 28 days.
Can I pour concrete in low temperatures?
Pouring concrete below +5°C is not recommended without special measures (heating, admixtures). At lower temperatures concrete sets more slowly and may freeze.
How do I calculate the amount of reinforcement for a slab?
Slab reinforcement depends on span and load. A Q335 or Q503 mesh is typically used (Ø8 or Ø10 bars at 15-20 cm spacing in both directions).
What is a stirrup and what is it for?
A stirrup is reinforcement that wraps around the longitudinal bars in beams and columns. It carries shear forces and prevents buckling of the longitudinal reinforcement.
What is the minimum distance of reinforcement from the concrete edge?
The concrete cover is at least 2.5-5 cm depending on exposure conditions. For foundations in soil, 5-7 cm is recommended.
How do I calculate the weight of a rebar?
Rebar weight: Ø8=0.395 kg/m, Ø10=0.617 kg/m, Ø12=0.888 kg/m, Ø14=1.208 kg/m, Ø16=1.578 kg/m. Our calculator automatically computes the total weight.
What is the difference between reinforcement mesh and individual bars?
Meshes (Q-meshes) are faster to install and more economical for slabs. Individual bars are used for beams, columns and more complex structures.
How do I determine the required insulation thickness?
It depends on your target U, the existing layers and the insulation λ: thickness = (1 ÷ target U − R of the existing layers and surfaces) × λ. The calculator works this out for the main new layer and, if you enter catalogue thicknesses, suggests the nearest larger one.
What is the difference between EPS and graphite EPS?
Graphite EPS has better thermal conductivity (λ=0.031-0.033 W/mK) than regular EPS (λ=0.035-0.040 W/mK), so a smaller thickness is needed for the same effect.
When should I use rock wool instead of EPS?
Stone wool is non-combustible, more vapour-open and better at damping sound, while EPS is lighter and usually cheaper. For taller buildings and fire barriers regulations often require a non-combustible material – check your country's rules and the ETICS system requirements.
Why is a wall's real U worse than the calculated one?
The calculation applies to a plain, homogeneous part of the cross-section. Anchors, thermal bridges (ring beams, balconies, reveals), moisture in the material and workmanship defects increase the real heat flow. So use manufacturer data and allow a margin.
How do I calculate stair dimensions?
Blondel's formula: 2h + b = 63 cm (±3 cm), where h is the riser height (16-18 cm) and b is the tread depth (28-32 cm). Our calculator automatically checks ergonomics.
How many risers do I need for a floor height?
Number of risers = total height / height of one riser. For a standard floor height of 280 cm and a riser of 17.5 cm you need 16 risers.
What are winder steps?
Winder steps are used in L- or U-shaped stairs instead of a landing. They allow a change of direction in a smaller space, but are less comfortable.
What is the optimal stair slope?
The optimal slope is 30-38°. Steeper stairs (>42°) are uncomfortable and dangerous, while gentler ones (<25°) require a lot of space and are impractical.
How do I calculate a spiral staircase?
Choose the Spiral type and enter the height H, outer diameter D, column diameter and rotation (e.g. 360°). The calculator picks the number of risers by 2h + b, places the walking line at 4/10 of the usable width measured from outside (the part near the column with treads narrower than 10 cm does not count as usable width) and checks the headroom one turn higher.
How many plasterboard sheets do I need for a ceiling?
Area ÷ board area (1200×2000 mm = 2.4 m²), plus a 10 % allowance. Example: 20 m² → 20 ÷ 2.4 × 1.1 = 9.2 → 10 boards.
What are CD, UD, CW and UW profiles for?
CD and UD are used for ceilings and linings (CD is the main carrying profile, UD the perimeter profile). CW and UW are used for partition walls (CW are the vertical studs, UW the tracks along floor and ceiling).
Why does the partition wall calculator count boards for both sides?
A partition wall is boarded on both sides. You enter the area of one side, and boards and screws are counted for both sides and the selected number of layers.
What is the difference between TN and LN screws?
TN screws fix boards to the metal substructure (with double boarding the 2nd layer uses a longer screw), while LN screws join metal profiles to each other.
How much joint and finishing compound is needed per m²?
The calculator uses roughly 0.35–0.5 kg/m² for joints and about 1.2 kg/m² for finishing the whole surface. Actual consumption depends on the finish quality and the manufacturer's instructions.
What does a binder-to-stone ratio of 1:15 mean?
There is 1 part of binder to 15 parts of stone (by weight). A 1:10 ratio gives more binder per kilogram of stone, and 1:20 less. Always match the exact ratio to the binder manufacturer's instructions.
Which layer thickness should I choose for a stone carpet?
The calculator offers 8, 10, 12 and 15 mm. Every extra millimetre adds 1.5 kg/m² of stone. The choice depends on the grain size and the use of the surface, so follow the manufacturer's recommendation.
Why is the binder rounded to packs of 20, 5 and 1 kg?
The binder is sold in those packs. The calculator rounds the need up to whole kilograms and combines packs so that the surplus over a larger pack is at most 1 kg.
Which epoxy system should I choose?
Systems 1–7 range from plain epoxy paint to primer with quartz and a self-levelling layer. The choice depends on the use of the floor, the load and the substrate, so follow the manufacturer's instructions. The calculator only works out the materials for the chosen system.
How is self-levelling epoxy calculated?
The consumption is 0.85 kg/m² for every millimetre of thickness, and quartz is added at a 1:1 ratio. For 50 m² at 2 mm that is 85 kg of epoxy and 85 kg of quartz.
What does quartz at a 1:1 ratio mean?
One kilogram of quartz sand is added for each kilogram of primer or epoxy. In system 6 the quartz goes only into the first epoxy coat, and the second coat has no quartz.
How does the 2D tile planner work?
Enter the room shape, covering type, format, joint width, laying pattern and start point. The planner draws the layout to scale, distinguishes whole from cut pieces, shows the cut dimensions and calculates the quantity to buy.
Which laying patterns does the planner support?
Straight (stack) laying, offsets of 1/2, 1/3, 1/4, 1/5 and 3/4, herringbone, an angled layout at a chosen angle, chevron (45°) and planks with the cut-off reused. You can also choose the start point, for example from the corner or with a joint in the centre.
Why is the quantity to buy larger than the room area?
The purchase estimate is conservative: every cut piece counts as a new tile, a 10 % reserve is added and the result is rounded up to whole packs. In practice some offcuts can be reused, so the real need is often lower.
How do I avoid very narrow edge cuts?
Move the start point, for example from the corner to a joint in the centre, or compare the start positions. The planner warns you when edge cuts are narrower than the set threshold and shows the narrowest one.
Does the planner support doors, niches and sloped walls?
Yes. Besides rectangular rooms it supports L and U shapes, your own outline and columns. In “Extras” you can enter angled walls (lengths and angles or coordinates), doors with a threshold and wall tiles with doors, windows and niches. Doors and passages between rooms are drawn in “Multiple rooms” mode.
Does the planner calculate skirting, underlay and transition strips?
Yes. The “Additional materials” card calculates skirting boards (tile skirting for tiles), underlay and vapour barrier for planks, and transition strips for doors and passages, with the number of pieces and rolls to buy; the items are also included in the PDF. The defaults – 2.4 m skirting, 10 m² roll, 20 cm vapour barrier overlap and 10 % allowance – are assumptions, not manufacturer data.
Can I transfer the area from the planner to other calculators?
Yes. For tiles, the tiled area, format and joint are transferred to the tile calculator, which then works out adhesive and grout, and the room area can be transferred to the self-levelling compound calculator. You do not type the data again and can still change it in the calculator.
How does the drywall calculator work out profiles and screws?
From consumption norms per m², for example for a ceiling CD profile 3 m/m², UD 0.5 m/m² and 17 screws per m². Profiles and boards are increased by the waste reserve. The norms are indicative, so follow the system manufacturer's spacing.
How many boards are needed for a 20 m² partition wall (one side)?
20 ÷ 2.4 (board 1200 × 2000 mm) = 8.3 boards per side; for both sides 16.7, and with a 10 % reserve 18.3 → 19 boards for a single layer on each side. Every extra layer multiplies the number of boards.
How is the amount of microcement calculated?
Consumption per layer (kg/m² per mm × thickness) × number of layers × area, plus the reserve, divided by the pack size and rounded up. Example (finish coat): 1.4 kg/m²/mm × 1.5 mm = 2.1 kg/m²; 20 m² and a 10 % reserve give 46.2 kg, so 2 bags of 25 kg.
Does the microcement calculator work out the cost?
Optionally, yes: if you enter prices it can also show the cost. Consumption, number of layers and pack sizes are entered per product according to the manufacturer's data sheet.
What affects microcement consumption?
The preparation and absorbency of the substrate, the application technique and layer thickness (consumption is given per mm of thickness: typically approx. 1.4 kg/m² for the finish coat and approx. 1.5 kg/m² for the flexible base coat) and the protective varnish. Always check the manufacturer's data sheet.
How do I enter an irregular terrace?
Choose your own shape and draw the outline with a finger or mouse, then enter the real side lengths. Add openings (post, manhole) as rectangles; the board and joist layout adapts to the outline.
What do the orange boards on the terrace plan mean?
They are cut pieces (shortened or ripped). Blue boards are whole. The list of cuts and offcuts comes from the same layout as the plan and the PDF.
Can the deck be laid diagonally or in herringbone?
Diagonally yes – the whole layout is calculated at the chosen angle. Herringbone is an estimate of pieces with waste, without a drawn layout.
How do I enter a fence on sloping ground?
For each section enter the ground height difference and choose stepped or raked. Stepped lengthens the posts by the step height; raked counts mesh and rails along the sloped length.
How do I add gates and passages?
In a section add a gate or passage with its offset from the start, width and gate type. Gates get their own posts and hardware; on the plan you can drag them along the section.
Can I send the footing concrete to the concrete calculator?
Yes. A button in the results opens the concrete calculator with the post footings (and the plinth wall if you have one) as elements.
How do I draw a room for plastering?
Tap “Draw it yourself (finger)” next to the room, draw the outline in one stroke and enter the wall lengths. For sloped walls you can edit the corner coordinates.
Does the plastering calculator also cover skim coat and paint?
Yes, optionally for walls and ceiling separately. It uses the same norms as the skim coat and paint calculator, so the results match.
How are window and door reveals calculated?
Reveal area is the opening perimeter (doors without the threshold) times the reveal depth. The opening is deducted from the wall and the reveal added if included.
How do I add roof windows, dormers and chimneys?
For each roof part add roof windows, dormers and chimneys. Openings are deducted from the covering, dormers add their own roof and valleys, chimneys add flashing.
Can the roof sides have different pitches?
For a gable roof enter the pitch of the other side; the ridge moves so the eaves stay at the same height. For more complex shapes use manual planes.
What does the gutter calculation include?
Gutters along the eaves, downpipes, outlets, hangers, corners and end caps – based on how the eaves run around the roof.
How wide is a saw cut?
It depends on the tool: thin blades and cutting discs about 1–2 mm, circular saws for wood 2–4 mm. Enter the real width of your blade – it is deducted at every cut.
What is the minimum usable offcut?
The length below which an offcut is no longer useful and goes to waste. Longer offcuts go into the register for future jobs.
Can one calculation contain several materials?
Yes. Each material or section is a separate group with its own parts, stock lengths and kerf, and is optimised separately – parts are never mixed between groups.
What is the difference between in-situ, loose and compacted states?
In situ is soil in the ground, loose after excavation (larger volume), and compacted after placing and compacting. The material balance is always compared in the same state.
What does a 1 : 1 side slope mean?
For every metre of depth the slope runs one metre horizontally. The slope is only a geometric input – slope stability is assessed by a qualified person according to the soil and conditions.
Do the dimensions refer to the bottom or the top of the excavation?
You choose: structure dimensions (working space is added), the bottom or the top of the excavation. If you give the top, the bottom is the top minus twice the slope times the depth; working space is never added twice.
Which pipe spacing should I choose for underfloor heating?
Spacing depends on the required output, temperatures and floor covering – the system table gives it. Smaller spacing gives more output but uses more pipe. Spacing must be at least twice the pipe's bending radius.
What is a bifilar spiral?
A layout in which flow and return run side by side spirally towards the centre and back, so the floor temperature is more even than with a serpentine layout.
Why is a manifold allowance needed?
Connecting the pipe to the manifold needs a little extra length at each end of the circuit. The allowance is added when choosing coils.
What is the difference between kW and BTU/h?
Both are units of power: 1 kW = 3412 BTU/h. A 9000 BTU/h unit has a cooling capacity of about 2.6 kW. The unit's electrical power is lower and depends on the EER.
Should I add a margin to the calculated capacity?
The calculator adds no hidden margins. If you add one, do it consciously and once – the model already ignores heat storage, which usually gives a higher peak for heavy buildings.
Where do I get the outdoor design temperature?
From design data for the location – weather data, the national annex of a standard or the design brief. The app does not fetch it automatically.
What is the difference between kWp, kW and kWh?
kWp is the rated power of the panels (DC), inverter kW is its AC output power, and kWh is the energy produced. A 10 kWp system does not produce 10 kW all the time.
How is row spacing on a flat roof calculated?
From the footprint of the tilted panel and the length of the shadow at noon on 21 December, when the sun is lowest. This does not rule out shading at other times of day.
What if PVGIS is not available?
The calculator shows that production was not calculated. You can choose the manual specific yield as a separate estimation method – it is never used as a hidden substitute.
Which types of measurement can be converted?
More than 80 measurement types in 14 groups: from basic quantities (length, area, volume, mass), mechanics, heat and energy to electricity, light, chemistry, radiation and data. You choose them in the “Measurement type” menu, which also has a search field. Conversion is only possible within the same type, e.g. pressure to pressure.
Why doesn't the table show every unit?
To keep it readable, the table shows metric and the most common units plus the two you selected by default. Turn on “Show all, including old units” for the full list. On the “Old and regional units” page the full list is on from the start.
What does the ≈ mark next to an old unit mean?
The value of that unit varied between regions, towns or periods. The converter uses the usual value for the stated region or variant, so the result is approximate. Units without the mark have a value fixed by law or confirmed by several independent sources.
Where do the values of old units come from?
From published sources: scientific and professional papers, publications of state institutions and encyclopaedias. Links to the sources are listed below the table for the units shown. Units whose value is not confirmed reliably enough are not included.
Why is the conversion result rounded?
For readability the result is shown with at most six significant digits, and values in the reference tables of old units with at most seven. The calculation uses the full conversion factors, and very large or very small numbers are shown in scientific notation.
How do I find a unit in a long list?
In the “From unit” and “To unit” menus, type a symbol or part of a name into the field at the top, e.g. “psi”, “ft²” or “acre”. Only matching units remain, under their group heading, and the collapsed “Other regions” are searched too. Without searching, scroll the list by dragging the bar on the right edge.
Why does the list of traditional units depend on the app language?
As the third group the converter shows traditional units used in the market of your language (e.g. tola and bigha for Hindi, 斤 and 亩 for Chinese) and moves units of other countries to “Other regions”. The list is shorter but nothing is lost: with the “Region” filter you can choose another region or “All regions”.
Can I enter a negative value?
Yes, for types where a negative value makes sense: temperature and temperature difference, angle and slope, voltage, current, charge, magnetic quantities and musical intervals, as well as units such as dBm. For length, mass, pressure and similar types a negative number is not allowed and the converter flags the input as invalid.
How do I calculate materials for a whole bathroom?
Open the bathroom wizard: you enter the room, door, window and shower dimensions only once, and the wizard calculates in turn the levelling compound, floor and wall tiles with adhesive and grout, and levelling clips. You get one material list in which identical items are merged. Add waterproofing, silicone and skirting separately.
How long should I wait between coats and before grouting?
Typically: grout floor tiles after 24 h and wall tiles after 4–8 h; the second coat of waterproofing after 1–4 h, and tiles on waterproofing after 2–12 h; levelling compound before tiling 12–24 h depending on thickness (about 2.4 h per mm). The values apply at about 20 °C; the product data sheet takes precedence. The work plan in a project puts these steps in order with dates.
How does the app calculate – can I check the calculation?
Yes. Below the result open “How was this calculated?”: you see the steps with formulas, intermediate results and rounding to packs, using the same values the calculator uses. Intermediate results are rounded for display only. Consumption rates and worked examples are on the Standards and Methodology pages.
Why does the app offer me 50 lb bags?
The default pack size follows your market: if the US measurement system is selected in Settings or your device is set to the US region, tile adhesive and levelling compound are offered in 50 lb bags (about 22.7 kg) and cement in 94 lb bags. You can pick another size in the pack menu, e.g. 25 kg; the required kilograms do not change, only the number of bags.
How do I remove ads for 24 hours? (Android only)
In the Android app only: tap “Ad-free for 24 hours” in the header, menu or Settings and watch one video ad to the end. For the next 24 hours there are no banners, full-screen ads or app-open ads, and PDFs come without an ad. If you close the ad before the end, no reward is granted. This option does not exist on the web.
Which waterproofing should I choose for a bathroom?
Under tiles you use liquid dispersion membranes (at least 0.5 mm dry) or flexible cementitious coatings (at least 2 mm). For a level-access shower and higher loads a 2-component cementitious coating is more common – always with sealing tape at joints and collars around pipes.
Why does the waterproofing calculator add 25 % to the thickness?
The minimum dry thickness must exist at every point and the substrate is never perfectly flat, so an allowance of at least 25 % is planned. You can change it; the material reserve is calculated separately.
How long should I wait after waterproofing before tiling or backfilling?
Typically 1–4 hours between coats of liquid and cementitious coatings and up to 12 hours before tiling. A thick bitumen coating dries for about 3 days before protection and backfilling. The data on the product's pack apply.