Extension roof

[Donutofdoooooom]

Hi all,

Looking for some advice on our current situation please -

Period property bought as a liveable doer upper, so lots needing done throughout, but it's the 'modern' extension which is causing us most issues.

Over the last year we've had 4 different roofers out for 6 or 7 different issues all for the same room essentially.

It has a dodgy velux that you can easily see has either been replaced lots or was just a bodge job to start with. One roofer mentioned that the type of window may not be suitable for the pitch of the roof, but couldn't say what a better option would be. Another said it was just badly installed.

We're also getting damp patches on the ceilings elsewhere which aren't from obvious issues such as broken tiles etc, hence so many visits from different reputable roofers, none of whom can say for certain where the issue is. One has mentioned that the type of tile is wrong for the pitch of the roof. Another has said the design is wrong as it's a lot of roof/water runoff to one area (back of original house runs onto extension roof which then only has a small gutter).

None of the roofers seem to be able to say what the pitch should be or what the right design should be, just that it doesn't 'look right'. These are bigger firms as well as small independents, when asked to both fix the issues and quote for a new roof.

The roof internally for the extension is odd, with quite low beams going across the middle of the room.

Who's best to speak to before re-doing it? Do we need an architect, structural engineer or a builder to advise on the correct roof before a roofer does it? I feel like I'm going round in circles!

Put some pictures up of the roof if you can , maybe someone help

Here's some pics

I'm not a roofer but I am an engineer and it's pretty obvious that flat window is too flat. It seems to be sunken rather than proud. The whole thing should be above the level of the roof. I'd say you need something higher at the back than the front so you get a triangular shape

Hard to tell from the angle, but there really isn't a lot of slope on that roof. Not sure if it's better or worse because of the curvy tiles (vs flat slates). You might be able to find a material that's better than what you have for shallow roofs.
I suspect the best alternative may be to have the roof redone with a higher pitch and have done with it, if you can afford it, rather than endlessly keep tweaking what's basically fundamentally unsatisfactory. We had a flat roofed extension and we had a pitch built on it, with slate. It's fine. Might at least be worth getting it costed? I agree with SuddenlyOld that the window looks too flat to have much hope it would ever stay dry.

We have similar issues since our extension, with various roofers coming out and all saying different things. Some blame the pitch of the roof, some say that veluxes always cause issues. One of them caused damage even just investigating. I don't even care about spending money on it, I just want a definitive answer about what is actually causing it. We've given up for now because we can't even get a roofer to come out and quote. Nightmare.

Your velux looks odd, like there is water getting stuck at the top of it with nowhere to go. Maybe it's getting in somewhere there. It just doesn't look like it's fitted right.

Velux windows should only be installed if the roof pitch is above 15 degrees. If your roof is too shallow it causes issues and they can leak. Also, there aren't many types of tiles that are suitable for low pitched roofs. We had this problem. Unfortunately it cost £££ to fix.

Common Problems with VELUX Windows Installed in a Low-Pitch Roof (velfit.co.uk)

Thanks everyone. We're happy to get the work done but same as @CurlyhairedAssassin we just can't get a definitive answer on what to do!

Roofer today said it's a 15 degrees pitch/slope but others have said less or blamed the tiles/install. A surveyor recommended a sheet metal roof so we're looking into that as an alternative (zinc/copper etc). Roofer today said not to go for them as it's just a fashion trend and to do a different tile or rubber.

The velux says 10-20 degree pitch is fine, but I think it was a bodge job install in the first place (previous owners).

We will need some form of roof light/window there as we need the light in the kitchen and in the back living room.

You can get an app on your phone that will tell you the pitch of you roof, just put your phone on the roof tile and it will do the rest. An angle finder will do the same but most people dont have one .

The roof light does look past its best and looks like its had a few attempts at trying to seal it.

At a guess i would say its about 15 degrees it looks low because the main roof is steeper.

If it were my roof i would retile with the same flat interlocking tiles as the main roof but fit them higher underneath the bottom row ,that way you would not need the the lead flashing that is between the two roofs. You can now get velux windows that are designed to be fitted on pitches lower that 15 degrees, if your pitch is lower than that.

Velux windows are very good and generally dont leak unless they are fitted on too low a pitch or the are not fitted properly.

we have 2 on a 15 degree roof and have had no problems ( fitted them myself ) Even though the tiles are designed for a minimum 17.5 degree pitch , they have been on 44 years with no issues.

It looks it a straightforward job im not sure why its proving difficult to find someone to do it ?

Looking at the photos again you could raise the pitch by removing 1,2 or 3 rows of tiles under the dormer and building the roof higher. This would give the roof light a better angle and wouldn’t effect the height too much under the other window.

The other damp patches you mention could be from condensation in the roof due to bad/no airflow ?