World War Two may have ended more than 70 years ago, but its effects are still being felt in the sort of work that Summit Cladding carries out.
How so? Well, although there was a house-building boom just after the war, there was still a shortage of steel. So much had been used to make ships, weapons, aircraft and ammunition that builders had to look to other materials.
One of these materials was concrete and in this case, concrete guttering. So-called finlock gutters were frequently used in the construction of post-war houses – but they can be a bit of a headache.
Concrete gutter problems
Summit recently completed a job to remove finlock guttering for Julia and her partner, who live in Camberwell, South London.
Mortar joints in horizontal guttering cause the mortar to become permeable over time, drawing moisture from rain into the building. Re-lining with rubberised compound or bitumen paint does not solve the problem because finlock gutters sit on top of the house. Water just lies in the gutter and does not drain away from the property.
Finlock gutters are continuous on the outside as well as the inside, so if it is cold on the outside that cold is transferred to the top of the upstairs walls. Being horizontal, some water sits in the gutter all the time and if it freezes in winter the cold transfer, known as ‘cold bridging,’ can have serious consequences.
Blocks become unstable
Condensation can occur, especially in cavity wall insulation, causing mould on the inside walls. And if that’s not bad enough, sagging can also occur above the window frames. Original post war houses were fitted with steel frames to support the finlock windows (there was obviously enough steel for that!) But with so much of a profile overhanging outside and the soft mortar joints, the blocks become unstable.
In such a situation, how can you discover the source of damp penetration? Is it moisture penetrating through a crack in the gutter, the gutter liner or the gutter sealing paint? It is an impossible task and there is little hope of finding the weakness.
Summit Cladding’s solution
The solution is to have the concrete gutter profile cut away with a diamond tipped disc cutter, then to attach timber to the wall with a foam filled maintenance free plastic fascia and modern pvc gutter and downpipes.
This not only reduces the weight overhanging the windows, it also permanently removes the chances of water penetration and insulates the outside of the finlock blocks.
The installation in Camberwell took three days to complete, including erecting and dismantling of scaffolding, and our clients had nothing but praise for our team who carried out the work.
Categorised in: Concrete guttering removal
This post was written by Summit Cladding