Sunday 7 February 2016

Roof Leaks

A whole series of "if it can go wrong it will" incidents seemed to be the theme for the latter half of 2015 (e.g. torrential rain in August that flooded the house (see earlier post), a sewage system so badly done it required daily manual flushes of outdoor pipework, venting windows that still leaked after refitting and resealing (see later post), some internal plumbing that was supposedly "no problem" proving to be only solved by what can only be described as a series of "mash-ups" which, in one instance is still not fit for purpose etc etc.

On top of these it was particularly disheartening to discover that an earlier leak, that had already, supposedly been rectified, had returned in exactly the same place. i.e. penetrating both the study area and scullery ceilings.

Fundamental to an earth sheltered design is the fact that the waterproof membrane covering the roof and the walls must at all times be waterproof.

Since the last attempt to seal these leaks the PV and solar hot water systems and a header tank for the hot water boiler in the cook stove had been installed on the roof on top of the earth sheltering. The first task, therefore, was to dig out the earth around the problem areas in order to gain access to the damaged membrane.

The slowness of the water penetration itself suggested that any puncture of the membrane would be minor. The roof drainage system was designed as a series of shallow contained areas between the various concrete beams that form an integral part of the roof and have a 10cm of  gravel on top of the membrane for drainage  and pipework to direct the water into the around the house drainage system. The suspicion was that the leak was from the small volume of static water that lies just below the level of the feeds to the drainage pipes. Identifying the leak was therefore a bit like "looking for a proverbial needle in a haystack". Couple this with the fact that over the suspect area was at least a metre of earth sheltering and you get a feel for the task. Motto get it right first time!!

After digging a series of holes through the earth sheltering the problem was located  beneath the recently installed header tank. Unfortunately in this exploratory work the piping to the header tank was damaged and therefore had to be repaired!! And so it goes on. You just could not make it up!!

Finally all was repaired and time will tell if it was successful.

Leaks in the ceiling of the study area that ajoins the lightwell.

Digging through the earthsheltering to find the leak.

Using rags to soak up the static water.

Resealing/repairing the waterproof membrane.