It is because there is nothing under the roof tiles to catch the leak and drain it away.
Low pitch roof tiles leaking.
Like freddie i can t get my head around building a flat roof then whacking a load of fixings through it.
My house has marley modern interlocking concrete tiles and a shallow pitch roof not that shallow but shallow anyway.
Areas such as eaves abutments and window surrounds require careful detailing to ensure a durable and watertight roof system.
Isolate areas when you run the hose.
Leaking low pitch roof.
If it is steeper than around 20 degrees it will be ok.
Low pitched roof tiles.
If you do get stains on your ceiling it makes our lives as roof leak busters a lot easier.
Roof tiles start to do poorly when the roof pitch gets less than 20 degrees.
This is because water tends to be stagnant on a flatter surface of a low pitched roof as compared to high pitched ones that lets the water flow freely downward.
When the batten support behind the top row of tiles is too low the tiles sit on a lower pitch.
The roof pitch on these is very low around 9 degrees on the lean to extension and around 12 on the kitchen extension.
Whether it is a problem depends on the pitch of the tiles under the capping.
The kitchen extension and the lean to extension are both have a single pitched roof with clay pantiles on them.
They lay flatter and this is the cause of the gap to the tiles on the row below.
The leak is right above the ceiling stain.
The whole flat roof below a fake tiled roof all seems like a complete bodge to me.
Start low soaking the area just above where the leak appears in the house.
We ve just moved into a house with a ground floor lean to extension attached to the rear of the house.
Interlocking tiles are generally suited to a minimum pitch of 22 5 degrees with the exception of going down to 17 5 degrees if there is an 18mm ply put in place on top of rafters felted counter battened breathable felt laid then battened out for a 100mm headlap on the tiles.
Get a flat roof material on it nowt else from the outset.
For example soak the downhill side of a chimney first then each side then the top on both sides.
It s not the flange that overlaps the adjacent tile that causes a leak if.
However at a low roof pitch components of a roof system may be working at the limit of their capabilities meaning more chance of failure.
If a leak is difficult to find enlist a helper and go up on the roof with a garden hose.
Of course it won t stop any water getting past the roof finish whether tiles or slates but the construction i mentioned for low pitch roofs will prevent any water that gets past the roof finish leaking into the building.
There is then a kitchen extension attached to the lean to extension.