Description
This 150mm EPS is a deep grey graphite polystyrene board, 1000 × 500 mm, for external wall insulation that is finished in render. At 150 mm it is one of the thickest boards in the system, chosen when a wall has to lose as little heat as possible and the building has the depth for it. It is part of the Renders World graphite board range, eleven thicknesses that share one format from 20 mm upwards.
One sheet of 150mm EPS covers 0.5 m², with a declared thermal conductivity of ≤ 0.031 W/mK.
150mm EPS: What You Get
Each board of 150mm EPS is a full 150 mm deep and measures 1000 × 500 mm on the face. The polystyrene carries graphite mixed in during manufacture, which turns it grey and lowers its thermal conductivity, so every millimetre of this thick layer works harder than white polystyrene would.
| Property | Declared value |
|---|---|
| Thermal conductivity λD | ≤ 0.031 W/mK |
| Reaction to fire | Class E |
| Thickness tolerance | T1 (± 1 mm) |
| Length and width tolerance | L2, W2 (± 2 mm) |
| Squareness | S5 (± 5 mm per 1000 mm) |
| Flatness | P5 (5 mm) |
| Bending strength | BS100 (≥ 100 kPa) |
| Tensile strength perpendicular to the faces | TR100 (≥ 100 kPa) |
| Dimensional stability, normal conditions | DS(N)2 (≤ 0.2 %) |
| Dimensional stability, set temperature and humidity | DS(70,-)2 (≤ 2 %) |
The Class E rating describes the EPS by itself. A rendered wall is classified as a whole system, so its fire performance is set by the system specification. The U-value and insulation thickness guide shows how to work out what 150 mm gives on your wall.
The 150 Means Millimetres
EPS 150 is also the name of a polystyrene grade sold as flat floor sheets. On this board the number means something else:
- 150 is the thickness, in millimetres, of a façade board for walls;
- it is not a floor grade, and it does not go under a screed, under a slab or into the ground.
Foundations, plinths and other work below ground or in lasting damp take a foundation board. The thickest one Renders World sells is the 100 mm foundation board, a separate product made for those conditions.
Why Choose a 150mm Graphite Board
- A deep layer in one pass. 150mm EPS goes on as a single layer, with no need to stack two thinner sheets.
- Graphite on top of thickness. ≤ 0.031 W/mK means a lower U-value for the same depth than white polystyrene.
- Matches the thinner sizes. The face is the same 1000 × 500 mm as all the EPS from 20 mm up, so reveal linings and the main wall line up.
- Square and flat. ± 1 mm on thickness and 5 mm on flatness give a true surface for the mesh over a large wall.
- Strength for the finish. At least 100 kPa in bending and in tension perpendicular to the faces.
- Dimensionally steady. No more than 0.2 % change in normal conditions.
Where a 150mm Board Goes
- External walls insulated by the bonded and rendered method or by the light-dry method, where the eaves, sills and window positions leave room for 150 mm.
- Stud walls, on the outer face.
- Cavity walls, in the enclosed or the ventilated slot, where the slot is that deep.
The adhesive bonds to concrete, cement and cement-lime plaster, bare brick, block and hollow block in ceramic or silicate, and aerated concrete.
A 150 mm layer moves the face of the wall a long way out, so check the depth at the eaves, the window sills and any downpipes before you order.
How Many Boards of 150mm EPS to Order
Order 150mm EPS at two boards per square metre. A full pack holds 4 boards and covers 2.00 m².
- A 40 m² gable takes 40 ÷ 0.5 = 80 boards, or 20 full packs.
- The reveals will not take 150 mm, so order thinner boards for them as a separate line.
- Take windows and doors off the wall area before dividing by 0.5.
Fitting the Board
Bond the EPS with a cement-based or polyurethane adhesive from the adhesives and basecoats for insulation boards. The wall has to be frost-free, load-bearing, even and sound, cleared of dust, dirt, lime, oil, grease, wax and old emulsion or oil paint.
- Prepare the background. Prime a very absorbent wall, weak cement or cement-lime plaster and rough aerated or cinder block with Uni-Grunt priming emulsion. Fill major hollows and cavities first with ZW 330 mortar or Plastering Mix M, which the shop lists as One Coat Dash Cover.
- Apply the adhesive. A continuous edge band at least 3 cm wide plus 6 to 8 patches 8 to 12 cm across, covering at least 40 % of the EPS and 60 % after pressing.
- Set the EPS. Press it on immediately with no more than 10 mm of adhesive behind it. Where the wall is even and smooth, a notched trowel can spread adhesive over the whole EPS face instead, leaving 2 to 5 mm after fixing.
- Prepare for the base coat. The face must be frost-free, flat, clean and stable; sand and dust graphite EPS before the base coat.
The fixings and mesh come next: see the insulation fixing accessories, the board fixing pattern and spacing guide and the EWI build-up and layers guide.
Keep Graphite Boards Out of the Sun
Thick or thin, graphite EPS follows the same site rules, and 150mm EPS is no exception:
- No warm EPS on the wall. Protect each sheet from heating while it is fixed and while the adhesive first sets, or the bond can loosen.
- Shade for the packs. Store them in their wrapping and out of direct sun, which can deform them.
- Weather protection. Hang scaffold covers and do not fix in snow, rain or strong wind.
A face exposed for a long time, especially to UV, can yellow; sand it back before the base coat. Acetone, nitro thinners, benzene and other solvents attack polystyrene, so keep them off the EPS.
When the wall's strength is uncertain, bond 8 to 10 cubes of polystyrene, 10 × 10 cm, across the façade and pull them after 3 days. A cube that splits within itself passes; one that lifts adhesive or a piece of the wall fails, and the insulation design has to solve that first.
150mm Among the Other Thicknesses
From 20 mm up all the EPS in the range is 1000 × 500 mm, so deeper and shallower sizes meet cleanly on one wall:
| Thickness | Sheets per m² | Full pack |
|---|---|---|
| 10 mm | 2 | order by the sheet |
| 20 mm | 2 | 30 sheets, 15.00 m² |
| 30 mm | 2 | 20 sheets, 10.00 m² |
| 50 mm | 2 | 12 sheets, 6.00 m² |
| 80 mm | 2 | 7 sheets, 3.50 m² |
| 90 mm | 2 | 6 sheets, 3.00 m² |
| 100 mm | 2 | order by the sheet |
| 150 mm (this board) | 2 | 4 sheets, 2.00 m² |
| 160 mm | 2 | 3 sheets, 1.50 m² |
| 180 mm | 2 | 3 sheets, 1.50 m² |
| 200 mm | 2 | 3 sheets, 1.50 m² |
Whether 150mm EPS or the 100 mm or 160 mm size is right for your wall is a U-value calculation for the complete build-up.
Ordering, Delivery and Returns
Renders World processes orders the same day when the stock is there.
- Delivery: quoted by the team after the order; parcels up to 25 kg go next day, pallets next day or in two business days on the economy option, always kerbside.
- Collection: from the counter at Unit 9A, Central Trading Estate, Southampton SO14 5JP, Monday to Friday 7am to 5pm and Saturday 7am to 12pm.
- Returns: goods bought directly from Renders World can go back within 14 days in their original condition; special orders and promotion purchases are excluded.
FAQ
What size is one board?
1000 × 500 × 150 mm, which covers 0.5 m². Two boards make a square metre.
How many boards are in a pack?
4 boards, covering 2.00 m².
Is this an EPS 150 floor sheet?
No. Here 150 is the thickness of a wall board. For floors choose a board made for floor loads; for foundations and the plinth use the 100 mm foundation board.
What is its thermal conductivity?
λD ≤ 0.031 W/mK. The U-value comes from a calculation for the whole wall.
Which adhesive should I use?
Cement-based or polyurethane. Lay an edge band with patches to cover at least 40 % of the EPS, at most 10 mm thick.
Will 150 mm fit under my eaves and sills?
Measure first. The finished wall stands about 150 mm plus adhesive and render further out, so sills, eaves and downpipes may need extending or moving.
What goes in the window reveals?
Much thinner EPS from the same range, cut to the depth the window frame leaves.
Technical Documentation