New Flat roof and new flashing but still a leak?

[Couperin]

Hey All,

Our detached house has a flat roof which has been suffering from leaks for the last 2 years in the same places. Its really got us down and we feel like we have nothing else to try as the 3 roofers that have been up there are out of ideas.

Pcitures of roof and leak: http://www.flickr.com/photos/115130724@N05/sets/72157640284584693/

I've posted a link to the pictures of the roof in its current state so any help from all you roofers/builders out there would be amazing and at least give us a little bit of hope to get this fixed.

The blue/grey stuff on the top part of the parapet wall is Acrypol and the big chimney and joining wall has also been smothered in Storm dry as well as the lower rendering in that section etc.

Thanks so much for reading

 

[foxhole]

I would say parrapet wall is the problem, the render helps prevent it drying and water exits the only way left, into you room. Had constant problems with mine as it had no capping, gave it a good overhang and it's been fine since.My epdm roofing runs up on to parrapet with capping over the top which prevent water entering the inner leaf of the brickwork.

 

[Couperin]

I would say parrapet wall is the problem, the render helps prevent it drying and water exits the only way left, into you room. Had constant problems with mine as it had no capping, gave it a good overhang and it's been fine since.My epdm roofing runs up on to parrapet with capping over the top which prevent water entering the inner leaf of the brickwork.

Thanks Foxhole!

Do you have any pictures of your roof you can post up so I can see? How much does re-doing with EPDM cost?

 

[Xenon]

The double row creasing tile is the DPM for the coping, these have failed leading to ingress. Wrap the coping in felt down onto the flat. Outer tile will need pointing, same as chimney, as well as new flaunching.

 

[Couperin]

The double row creasing tile is the DPM for the coping, these have failed leading to ingress. Wrap the coping in felt down onto the flat. Outer tile will need pointing, same as chimney, as well as new flaunching.

Thanks for answering Xenon! Yeah I think re-pointing the chimney, re-doing the flaunching and coating it in something like that storm dry that everyone's going on about recently would be a really good idea.

Would it be a good idea to take off the creasing tiles completely and build up from there? What would go on top? Coping stones or lead or something like that?

 

[ree]

I think that you are fighting a losing battle. There are too many variables that could lead, if not now, then to future headaches of leaking.

Perhaps bite the bullet and remove the parapet, partially re-build the stacks and go for a pitched roof.
Where you have an odd, long footprint then maybe design in a shed roof.

A pitched roof could incorporate a loft conversion and/or better insulation.

I understand the expense etc. but i only tell you what i'm seeing and you, of course, will take what you want and make your calls.

Given its age, the dashed rendered elevations will need examining before tying into any new parapet if thats the way you go.

 

[palaceray]

You cold consider reducing the height of the parapet and fixing ply to the remainder of the wall and fixing felt over the top or if you want the best possible job clad the wall in Lead.

 

[Couperin]

I think that you are fighting a losing battle. There are too many variables that could lead, if not now, then to future headaches of leaking.

Perhaps bite the bullet and remove the parapet, partially re-build the stacks and go for a pitched roof.
Where you have an odd, long footprint then maybe design in a shed roof.

A pitched roof could incorporate a loft conversion and/or better insulation.

I understand the expense etc. but i only tell you what i'm seeing and you, of course, will take what you want and make your calls.

Given its age, the dashed rendered elevations will need examining before tying into any new parapet if thats the way you go.

Thanks for your reply Ree.

To be absolutely honest I would swap a flat roof for a pitched roof anyday but the cost (especially London prices) and designing it for our odd wedge shaped house would be sky high. On top of that we have to apply for planning permission which may or may not be approved (likely not) and live for a few months in a tip without a roof while the pitched roof is fitted.

I think at the moment its not possible so we'll just have to work out how to fix these Parapet walls.

 

[Couperin]

You cold consider reducing the height of the parapet and fixing ply to the remainder of the wall and fixing felt over the top or if you want the best possible job clad the wall in Lead.

Thanks for your reply Palaceray.

Sounds like a good idea although I cant imagine what it would look like on the other side of the parapet wall.

Do you reckon you could link some pictures of what you mean?

 

[ree]

If you could scan a plan view of the roof indicating areas of visible damage to rooms below (as in your pics) then perhaps some pattern might be established.

Just a thought, maybe drop the parapet to a height say one brick above the lead flashing, (thereby eliminating the tile creasing and render) and cap with sloping concrete flag cap stones.

Flags would give you an outer and inner lip cover. To slightly fall into the roof.
It might also be possible to incorporate a full width DPC.

You would need a tower for the parapet and the stacks but a full scaff might be avoided - depending on HSE



Thing is, you will have to water test the cap sheet field and upstands before anything else because if they are leaking then its a re-think.

Given the large dormers and solar panels of your neighbours then Planning shouldn't object.

Slathering with various remedial agents will only work for a time then its back to square one.

Why were the torch and gas bottle on the roof, have recent repairs taken place?

 

[Couperin]

If you could scan a plan view of the roof indicating areas of visible damage to rooms below (as in your pics) then perhaps some pattern might be established.

Just a thought, maybe drop the parapet to a height say one brick above the lead flashing, (thereby eliminating the tile creasing and render) and cap with sloping concrete flag cap stones.

Flags would give you an outer and inner lip cover. To slightly fall into the roof.
It might also be possible to incorporate a full width DPC.

You would need a tower for the parapet and the stacks but a full scaff might be avoided - depending on HSE



Thing is, you will have to water test the cap sheet field and upstands before anything else because if they are leaking then its a re-think.

Given the large dormers and solar panels of your neighbours then Planning shouldn't object.

Slathering with various remedial agents will only work for a time then its back to square one.

Why were the torch and gas bottle on the roof, have recent repairs taken place?

Thanks Ree!

I'll try and draw a plan out of the top of the house and mark out the trouble spots.

I like your idea of dropping the parapet wall slightly and adding copping stones to the top with a DPC layer underneath. Would this work and would it be expensive? what style coping stones would I need?

I just want to get it sorted so if the parapet is causing the water ingress then I'll get that fixed but if its the roof then I'll layer it in fibre glass or plaster it in butamin. I just need to stop the leaks for at least 5 years maybe then we'll invest in a pitched roof.

 

[Couperin]

Hey Ben,

Thanks for helping out here. Yep the roofers have all mentioned about the second chimney. It definitely needs work and it is causing water to come into the house so we're going to get that redone 100%. Unfortunately, this is on the other side of the house to where the leak on the wall is.

If you count the pictures, the pictures 26 and 27 are right above the wall leak. I'll draw a quick rough sketch up and post it up for you guys to see.

 

[catlad]

You could lay some roofing felt over the parapet wall and then clamp with the aid of some batons either, side you would need some long clamps to secure the batons, and that way you should be able eliminate things.

 

[Couperin]

You could lay some roofing felt over the parapet wall and then clamp with the aid of some batons either, side you would need some long clamps to secure the batons, and that way you should be able eliminate things.

Hey Catlad,

Thanks for your reply. Do you mean like big G clamps to fasten to the parapet walls? Thats a really really good idea?

That way we'll know if its the parapet wall or not!!!!

Thanks Catlad, I'll post up the result once its done

 

[Couperin]

Just thought I'd let everyone know that it was the parapet wall in the end. It was painted with a polymer paint and sealed and we haven't seen any leaks yet.

Going to paint the house next year to seal the other side too. Thanks to everyone for your help and ideas.