Spray Polyurethane Foam Roofing Application

If the sprayed polyurethane foam (SPF) was not apllied correctly, the roofing ply starts to dust, delaminate and it will loose it´s hydro-insulation capabilities.

Minimum roof pitch for the spray foam roofing

The minimum roof pitch suggested for SPF roofing is 3 degrees (on all parts of the roof, no 1 degree valleys).

Spray urethane application rules

- the roof surface has to be dry, clean, degreased;
- the air temperature must be minimum 10 Celsius degrees;
- the roof temperature must be minimum 12 (but better 15) Celsius degrees;
- the air humidity under 75%;
- no or almost no wind;
- every single layer of the PU must be maximum 15 milimetres thick (0.6 inch);
- the total minimu thickness (of all 2 or 3 layers) has to be 30 milimetres or more (1.2 inch).

When to apply the spray polyurethane foam roofing

From the above rules you see that the SPF application is more or less seasonal work, best done during the local summer. If the above mentioned rules are not kept, the declared functional properties of the polyurethane foam cannot be guaranteed.