Anti-Condensation Roof Sheet – 10mm Foam-Backed Profiled Steel, Anthracite

If your garage, workshop or stable rains on the inside every cold morning, the roof is not leaking. Warm moist air rises, meets the underside of a bare steel sheet that has been chilled overnight, and condenses on it. By mid-morning it has gathered into drips that land on tools, feed, machinery and everything else you were keeping dry. A single-skin metal roof will do this every winter for as long as it is up there.

This sheet solves it at the source. A 10mm layer of rigid polyurethane foam is factory-bonded to the underside of a profiled anthracite steel sheet, so the surface the warm air actually touches is insulated foam rather than cold metal. Keep that surface above the dew point and the moisture never condenses in the first place. There is no membrane to sag, no liner to build, and nothing extra to fix — you sheet the roof exactly as you would with a plain profile.

Be clear about what this does and does not do

A 10mm foam backing is a condensation control layer, not a thermal insulation upgrade. It is the right answer for an unheated or lightly heated building — a garage, workshop, store, stable or machinery shed — where the problem is drips rather than heat loss. If you are heating the building properly and want it to stay warm, you want a full insulated composite panel instead, and our 80mm PIR Insulated Roof Panel is the product for that job. Ventilation still matters here too: the foam manages the surface temperature, but a completely sealed building with a constant moisture source will still find somewhere to deposit it. Keep eaves and ridge able to breathe.

Technical specification

Frequently asked questions

How many sheets do I need?
Work on the 896mm cover width, not the 1000mm overall width — the difference is the side lap. Divide your roof width by 0.896m and round up. For the length, pick the sheet that runs ridge to eaves in one piece where you can; end laps on a shallow roof are the first place water finds a way in.

Will it stop condensation completely?
In a normal unheated garage, workshop or stable, yes — that is exactly what the foam is there for. What it cannot overcome is a building that is sealed tight with a large ongoing moisture source inside it, such as wet livestock bedding, a running vehicle, or drying laundry, with nowhere for that moisture to escape. Condensation control is a combination of surface temperature and ventilation, and this sheet handles the first of those two.

Can I fix through the foam in the normal way?
Yes. The sheets are through-fixed into purlins in the usual way with self-drilling roofing fixings and sealing washers, sized to allow for the extra 10mm of foam. Set your fixings so the washer compresses against the steel crown, not into the foam.

What gauge is the steel?
The manufacturer does not publish a steel gauge for this sheet, so we are not going to state one. If your specification depends on it, contact us before ordering and we will get it confirmed in writing rather than guess.

Is the foam damaged by handling?
It is a rigid closed-panel foam rather than a soft fleece, so it handles far better than a fabric-backed sheet, but it will scuff if you drag sheets face down across a hard surface. Lift rather than slide, and stack foam-to-foam.

Longer sheets

This sheet is also produced in 5m, 6m and 7m lengths. Those lengths are currently out of stock with our source and we will not list a length we cannot actually supply, so only the 3m and 4m are shown. If you need a longer run, get in touch and we will tell you what the lead time looks like.

What else you will need

• 80mm PIR Insulated Roof Panel — the step up, for buildings you actually heat
• Box Profile Steel Roofing Sheets 32/1000 — plain single-skin sheeting for open-sided or unenclosed areas
• Aluminium Half Round Gutter System 125mm — to carry the water away at the eaves
• Freestanding Roof Edge Protection Guardrail Kit — non-penetrating edge protection while you sheet