A leak in the roof just above a light fitting – what are the chances of that?

What are the chances of having a leak in a 50m2 roof JUST above a light fitting?
Well, we had one, thus it’s unlikely that we win the lottery this year.

In our bathroom we had a ceiling light (one of the glass bulbs) which started to be a warm water aquarium each time it rained. The bulb nicely heating the water up whilst producing some strange light effects.

The former owners had sealed the roof space so there was no way to get to this. Option 1. Get on the roof and check. Option 2. Put a small opening from the outside allowing access to the roof from inside.

I opted for nbr 2 and waited for some warmer sunny weather. Amazing on a 50 m2 roof just one tile was cracked right above the opening for the ceiling light. Unbelievable!

The temperature differences and sometimes harsh climate plays havoc with materials. On shallow roofs this can cause misalignment of tiles over time. Roof pitches here are very shallow and under felting is not normally done so strong winds can push water in. The advantage is that roofs rarely need tying and the outward pressure on the walls is very low. To avoid future surprises we decided that, as it is a very well ventilated roof, we will simply put plastic foil down. Loosely so there is air movement even from the underside. In future any misalignment or cracks may allow water in but it can evaporate without doing any harm until fixed. Checking the foil and beams will show up future leaks.

We used the ambiguous clear foil available in all fereterieas which is 4m wide and costs about 1.80Euro a meter. I simply used the PVC glue for the plastic pipes to fix and seal the overlap.

 

An old stable door and a bit of timber now make this opening a new fixture. Imagine the window black, the wall rendered and painted (yellow). Poko a poko as they say.

Expat

PS. Roof tiles specifically old ones have undergone significant design changes in anticipation of more rain or simply experience. Some design changes make it impossible to mix new and old tiles! So it is somewhat important to keep the heap of old tiles one has found somewhere in or around the property. It also helps to check with friends, other restorers and neighbours to get replacements. It’s not just cheaper I think it looks better than a brand new roof on an older property.

PPS. Sorry for the blue sky and sunshine. This is Galicia. Last year we froze this year it’s 20+ at noon.