Insulating a flat roof

with TONZON Thermosheets


Many problems have been experienced when insulating flat roofs in the Netherlands. Nevertheless, flat roofs are very easy to insulate from the inside, using TONZON Thermosheets. Read more below.


Insulating a wooden roof from the inside


In the Netherlands, many problems have arisen when insulating flat, wooden roofs. The external roofing layer is waterproof and provides a very high vapour barrier. This means that water vapour from the indoor air cannot escape through the roof covering. An uninsulated wooden roof must therefore process a lot of moisture. The wood can be very damp at one moment, because it’s cold. A bit later, the wood can be bone dry again, heated by sunshine on the roof. The moisture created during cold periods escapes during warm periods through the gaps between the wall and the roof decking. Insulating a flat roof can lead to problems, as the water vapour in the interior air space, will reach the colder, inside surface of the roof. In cold periods, this water vapour condenses but, because of the insulation, will not easily evaporate again. Moisture accumulation occurs, which means that the wood remains almost constantly wet. It is therefore often recommended to insulate the roof from the outside, not from the inside.


What to look out for


Nevertheless, you can insulate a flat roof very effectively from the inside, with TONZON Thermosheets. This requires attention to the following:

1. Provide a highly effective vapour barrier on the warm side (i.e. not the roof tile side), with good edge sealing (using foil adhesive), so that very little water vapour is allowed to enter the structure. TONZON Thermosheets are known to have a very high vapour barrier effect.

2. Ensure that the layer of air between the upper side of the insulation and the underside of the roof has some connection to the outside air, so that moisture can escape to the outside. Often, the existing seam between wall and roof is sufficient. So do not glue the Thermosheets directly to the roof decking, but allow for layer of air between insulation and decking.

Read more about roof insulation here.


Insulating a suspended or system ceiling

There is often a lot of unused space above a suspended ceiling. This is a good place to mount insulation. Yet it is not always easy to properly insulate this space, as it is interrupted by the structure to which the suspended ceiling is attached. With TONZON Thermos Cushions, insulation can be placed in such a way as to avoid these obstacles relatively easily, so that a good end result can still be achieved. Thermos Cushions are made of reflective foil, and contain motionless air. This is an effective combination for stopping heat flow, using relatively little material. As the system uses air, and warm air rises, its performance in winter will be slightly less than in summer. The added insulation value in winter is around Rd = 2, while in summer it can be as high as Rd = 5. Read more about insulation values here.



Insulate your flat roof from inside - and avoid a lot of extra work


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