THERMASEAL

The Problem

The most common failure with slated and tiled roofs start with movement and slippage due to the fatigue of the fixings and nibs.  Once slippage starts you can assume that all of the fixings are close to failure. The term nail fatigue is often mentioned in surveyor’s reports.  Hooked or nibbed tiles very often fail due to frost attack to the hook or nib.  Many older roofs have no under felt, or earlier forms of felt can easily become tattered or torn and can be prone to wind driven rain, snow, storm damage and gale-force winds. Condensation in roof voids along with pipes and tanks freezing in cold.

The Solution

Previous attempts to hold slates and tiles in place after nail fatigue had set in, failed. This was done by using lime based mortar (torching) on the under surface, but they soon decay.  The system was first shown on BOC’S tomorrows world in 1977, the spray applied rigid polyisocyanurate foam treatment has been used since the early 1970’s as a modern form of torching in all types of roof construction in both the public and private sectors.  Thermaseal is applied to an average depth of 50-85mm on the under side of the slate/tile to secure any movement or slippage.

The Survey
Thermaseal surveyors make sure of the suitability and special requirements for every individual installation. All aspects of the roof are given their full attention, before any installation any remedial works required to the outside roof, gulleys, valleys and flashings etc are carried

Barn Conversions

Spray-applied polyurethane foam can provide the most cost effective method of converting loft and barn roofs and walls and meet the ever-increasing demand for energy efficient buildings. PU foam is applied directly to the underside of the tiles or roofing felt, creating a warm deck construction without the need for a ventilated airspace. Only 75mm thickness is required to achieve a U-value of better than O.25W/m’K. This fits snugly between the rafters so that they may be left exposed as an aesthetic feature.

Problems of evening-up irregular surfaces, such as closing the ventilation off at eaves level, are easily overcome by building up the foam to the required profile. After some attention to trimming and removing over spray, a single coat of bonding plaster is laid to leave an attractive, authentic finish. The design complies with BS 5250: 2002 ‘Control of Condensation in Buildings’ with no occurrence of surface or interstitial condensation.