House Roof Insulation

Websters spray foam house roof insulation could be your solution if you are facing the potential cost and inconvenience of re-roofing. We have over 30 years experience of roof insulation and employ our own teams of highly skilled and friendly engineers.

All work is guaranteed and the insulation is maintenance free for the life of the roof. Websters Insulation are an approved installer of Duratherm which holds BBA Accreditation No. 10/4771 in respect to the materials manufacturer Isothane Ltd.

Duratherm is recommended for spraying under tiles / slates, under-felt and breather membranes. It meets building regulations and seals your roof from draughts and wind driven rain all in one application.

Most houses have 100mm fibre at ceiling level, so using Duratherm roof insulation at 105mm (typical rafter thicknesses) can bring the U Value down to 0.18. This is known as a hybrid roof, and using Duratherm allows you to meet Building Regulation, without extending the battens in most cases.



Existing House Roof


New Build House Roof


Loft Conversion


Timber Framed Walls


Roof Stabilisation


Existing Ceiling Voids (Dorma Type / Vaulted Ceilings)


By ensuring that the ceiling is sealed around any pipes etc to stop moist air seeping into the loft space, you can reclaim your loft by boarding out for precious storage space.

With Duratherm installed in the roof, you won’t get any more draughts through tile gaps, loose tile debris, slipping tiles or slates, or condensation forming on the underside of the roof covering.

There is no need to fit any additional ventilation aids with Duratherm, as its BBA certificate allows you to spray direct to tile, slate, sarking felt, sarking boards, and also breathable felts. The roof does not need to be ventilated, so the roof space is warmer meaning the water pipes and tanks can’t freeze, even in extreme winters like the ones we have recently experienced.

DURATHERM® House Roof Insulation is an HCFC AND CFC FREE two component, 1:1 ratio, rigid foam system which when processed through suitable spray machinery (Graco, Gusmer, Glas-Craft) will produce a rigid foam of approximate density 35kg/m3 with exceptionally good compressive strength. Service Temp range -15oC to 70oC. When tested to BS476 part 7 the foam achieves a Class 1 surface spread of flame.

DURATHERM® roof insulation is used for:

5 Reasons why you should use DURATHERM® roof insulation:

DURATHERM® can be used to upgrade the thermal performance of roofs, floors or walls of any property, to meet current building regulations. The best solution for house roof insulation to any existing or new build house roof, barn conversion, loft conversion etc…

The Following photographs were taken whilst spray foam insulating the outside of a large house roof in Oxford, by our engineers. Notice how the foam easily follows the curve of the roof where other products such as rigid board insulation would not.

We can find fast, efficient and economical solutions to most potential house roof insulation requirements, using this most versatile of products. It has a wide range of uses and applications and is equally suitable for new build or older constructions, as it bonds to most surfaces. Without insulation a normal roof is a poor barrier against heat loss and so creates unnecessarily high fuel costs and leaves plumbing unprotected against frost damage.

This is the BBA endorsed spray foam insulation system known as Walltite, from a well known chemical manufacturer called BASF. They make spray foam and cavity injection foam systems and a property in Lincoln benefited from both the cavity walls and the pitched roof being insulated with Walltite foam. The roof received a 200mm thickness of Walltite, and the 120mm cavity walls had a full-fill of Walltite cavity foam insulation. This method exceeds building regulations and will provide a well insulated, air-tight dwelling for its happy residents for years to come.

BASF Walltite spray foam is suitable for house roof insulation, cavity wall insulation, flat ceilings and soffits, and even loft floors.

So, when you think of house roof insulation, think of Websters Insulation.

Free Quote

Please fill in the form below and we will get back to you as soon as possible with your free quote.

Alternatively, you can call us on 01405 812 682 or email us at