London Flat Roofing. 154c Fleet Road, Hampstead, London NW3 2QX
This video shows detailed drawings on how a warm flat roof is constructed. I link to two other videos, one on cold flat roof construction and one that’s an in depth comparison between cold and warm flat roofs, also showing thermal imaging of poorly performing, insulated flat roofs.
Part L of the Building Regulations and insulating flat roofs. Part L has always been an issue with flat roofing as some people don’t want to insulate their flat roofs.
This old flat roof above a shop in Pinner was leaking for some time. As it’s a walkway to the flat above, the new roof had to have tiles over the top. This roof was well constructed so we were able to use normal concrete tiles rather than promenade tiles. The roof walls were insulated using Kingspan insulation to a depth of 100mm, then a new decking over the top with the Kemperol V210 System.
This new flat roof has been laid using the Kemperol v210 System. We laid the system over new decking over insulation which forms a warm roof that conforms to the new building regulation standard Part L1b. Promenade tiles have been laid over the new Kemperol flat roof to protect it from people walking on it; the promenade tiles are standard light weight tiles.
Flat roof insulation and a liquid applied roof finish, not a liquid rubber but a material called Kemper. Forming a box gutter on a flat roof can be complicated; we now use the Kemperol v210 System. Kemperol v210 stays flexible for the lifespan of the roof. Liquid flat roofing materials are superb for use on flat roofs and box gutters that have lots of detail. If you have ever worked with mineral felt, just think how hard it would be to dress the felt inside this box gutter!
A lot customers have never heard of Part L of the Building Regulations and I find myself explaining these regulations all the time, so I have uploaded this video and hope that it helps anybody looking to find out more. Part L and flat roofing are becoming more and more tied together. We always try to form a warm roof for our flat roofs, we find that a warm roof construction for flat roofing is by far the best flat roof.
What is a warm roof? What is a cold roof? In this video I show a warm roof construction on a flat roof that has gone wrong, I show how a warm flat roof should be built and how a cold flat roof should be built. The term “Warm Roof” acutely refers to the space under the roof insulation and not the roof itself. The same applies to the term “Cold Roof”.
The Kemper system is laid wet into a fleece, as you can see we’ve even covered the internal surfaces of the parapet walls on this job. By doing so we remove the need to use flashings, and the flashing details are normally what go wrong on a roof as it’s approaching the end of its lifespan.
One thing’s for sure, all the insulation on the roof will have to come out and we will have to probe the timbers to find out their moisture content before we can even think of re-roofing. We have our suspicions that not only was the vapour barrier not installed correctly on this roof, but the roof was also leaking in places. I will post more videos as the job progresses.
This roof is leaking or sweating, so we’ve been asked to make some inspection holes to see if we can determine the cause of the problem. We first noted that the falls on the roof are incorrect and inadequate, as water is puddling. For a 4 year old building, this is not a good sign. One of the things that kills a flat roof is incorrect falls, and that is the case here.