The Mad Surveyor

Concerning the cost of installing polyurethane spray foam, polyurethane foam is a high performance product that insulates seals and bonds and requires no ventilation because it creates a warm roof. It is also professionally installed by typically 2 operatives per onsite van. Clearly you cannot get this for the price of an inferior product like mineral wool. The foam specified will be 2 component (polyol and isocyanate) rigid, fast cure foam, British Standard Class 1, fire rated, high density (k value 0.020 W/m2.k) and 95% closed cell affording breathing properties to the timber substrate. This is a high performance product and bears no relation to the cheap canned one component foams either used by our competitors or found in the DIY market. Like all things, you get what you pay for.

The foam will draft proof (air leakage is a major source of energy loss), insulates (reduces transmission of energy by thermal conductivity) and sound proof to a large degree, The depth of foam applied range anywhere from 40 mm nominal to 150 mm nominal and is governed by the U value that is required and the k value (thermal conductivity of the insulation material). Depth of insulation foam is given by factoring the U value required into the k value and normalising for units to get the depth in millimetres. We do this calculation on behalf of the customer and can if required do proof of calculation if these are needed to support a planning application. He have designed the industry’s first U value calculator for composite substrates and will produce a thermal resistance R value as the sum of (R0 + R1 + R2 + … etc) to get the U value needed. From that it is a straightforward to get the depth of foam needed by the foam’s k value - (d = k/U and then normalise for millimetres).

We heat fuse the foam to the substrate at high temperature (120 degrees) and at high pressure (600 psi). We essentially bring a polyurethane factory to the customers door step (a large van with £70,000 of foam making equipment) and make the foam on site. We guarantee the foam for a minimum of 25 years.

Polyurethane foam is the best insulation solution by far and will out perform, products like mineral wool (which always need venting thus creating drafts that suck heat out as mineral wool does not seal) by a factor of 6 to 1 under real world conditions. Laboratory results for calculating U values rely on heat box still air conditions and this gives polyurethane foam a typical performance advantage over mineral or glass wool by a factor of 3 to 1.  If you want the best it is has to be a polyurethane foam solution. 

IsoSpray now also now supply professional ‘DIY’ of two component foams suitable to be sprayed at ambient temperature. If you are capable of spraying and doing the job yourself then this might help reduce your costs if cost is your primary concern. IsoSpray always guarantee the lowest rates for all products for all work we do.