We have had a couple of problems with water leaking into the building – one from under the floor and the other through the roof.
When the new concrete floors were laid in the extension, a 75mm insulation board was put down first and then 75mm of screed on top. The underfloor heating pipes are fixed to the top of the insulation boards and the screed is laid on top. The hot and cold water to the bathrooms, along with the heating for the towel rails, is run underneath the insulation. We pressure tested all of the pipework before laying the screed, but unfortunately it looks as if we have a leak in one of the downstairs bathrooms. The underfloor heating is fine since it is maintaining pressure (if there was a leak the pressure would drop) and the floor seems to have started to dry out now that we have turned off the water to this part of the building. Next job is to dig up part of the screed to find the leak. This shouldn’t be too bad as the wet marks in the floor are giving us a clue where the leak is! The last place to dry on the floor is probably where we will find the leak! A job for this week.
It looks as if the leak is under the floor in the bottom right hand corner. As the floor dries out (we have turned the water supply off to this area), it slowly reveals the location of the leak. The water has travelled along the gaps in the insulation boards under the floor and then soaked through the concrete screed.
The next problem is in my study. Rain appears to be getting in the joint between the roof and the wall. The roof here is a simple mono pitch roof. We have increased the height of the lead upstand on the outside. This has improved the situation, but rain is still clearly getting through. We believe that the rain is soaking into the exterior stonework and then running down behind the lead. One way of solving this is to treat the exterior stonework with waterproofer – something like Clear Cladding from Belzona. Unfortunately, all of the suppliers have been closed over the Christmas period, so we will have to wait until the new year before addressing this one.
It looks as if rain is penetrating the joint between the roof and the outer wall. The roof here is a mono-pitch. Putting an additional lead upstand has helped, but the rain is still soaking through the plasterwork.
This has dried out a bit over Christmas, but clearly rain is still penetrating this part of the roof joint.