Repaired Flat Roof - Can It Be Tested?

[jagillham]

Hi,

Thread #3 for defects on this house we are looking at buying!

Currently waiting to hear back from the vendor regarding the history of the flat roof on the extension. We know the extension is no older than 2012, and we also know it must have leaked at some point due to evidence of water staining on the ceiling beneath. I am no roofer, but I am assuming by the visually displeasing roof that some kind of repair(s) have happened at some point. What I do not know is what has been done, and if there is any way of testing it except maybe spending the afternoon there with a hosepipe?! No doubt vendors are going to say it did leak, but it's fine now...

Problems seem to me (as a layman!) that...

- Edge of roof is not level along the length
- Walking on the roof there was some 'bounce' in places
- Repairs seem rather messy / unprofessional
- Some kind of extra layer has been applied

Any advise gratefully received. I could really do with knowing if we'll need a replacement roof or not should we decide to go ahead.

 

[datarebal]

it does not need testing... its a mess and will fail

 

[jagillham]

it does not need testing... its a mess and will fail

Rather to the point! Haha

What do you think, “just” a case of taking the whole lot off and having it done again? Maybe in rubber or fibreglass?

 

[datarebal]

strip it off, re think the weathering to the pipe works, Possibly get them boxed in then weathered to the box much cleaner and reliable.
Personally I would not class this as a diy job.

 

[catlad]

Yep that is definitely going to leak if not
leaking already.

 

[jagillham]

Don't worry, no plans to do this myself!

Going to have to renegotiate the price of the house to take into account getting this redone

Anybody care to have a rough crack at the price of redoing it in GRP or EDPM? Total roof is approx 6m x 3m. Pipes as shown, as is roof lantern. Back is obviously the house, and one side is upto a parapet wall on the neighbours extension. Property is in Kent.

£1000, £2000, £5000, £10,000 ?!

 

[freddiemercurystwin]

Is there scope to get those drains out of the way? ie outside the extension, I think it would be unreasonable to apply the costs of drain redirection into the sale price but for long term roof reliability I would do that myself. If it wasn't an option I would walk away. That would mean about a £1-3 reduction.

 

[datarebal]

if the soil pipe and waste are all boxed in above the flat roof, the ubbiflex flashing raised up to suit then weathering just the soil and one waste shouldn't be a big deal

 

[jagillham]

Is there scope to get those drains out of the way? ie outside the extension, I think it would be unreasonable to apply the costs of drain redirection into the sale price but for long term roof reliability I would do that myself. If it wasn't an option I would walk away. That would mean about a £1-3 reduction.

Maybe so, you'll have to use your imagination a little as the permitted development plans were not the final design.

So here is the plans, showing the drain locations.

And this is what they did do...

Upstairs for reference (above the 'family room')

It seems there is access to the drains here, I've just caught the manhole cover in this photo. (Yeah, that wall's wet!)

And this is the stench pipe which helpfully goes through the roof!

 

[jagillham]

...That would mean about a £1-3 reduction.

Sorry for double post. Is that £1k-£3k approximate cost for redoing the roof?

 

[Mike10]

Shame the bit of stench pipe through the roof isn't actually connected to the rest of it though.

 

[jagillham]

So, looking at this again in a bit more detail - would it be fair to say it's fundamentally a design issue here?

The pipes come out of the bathroom too low / roof is too high. End result being the bath & toilet waste pipes having to go through the flashing. Which in turn means where these pipes meet the roof, it's the connector elbows that go though the waterproof layer, not a straight section that could be sealed with a suitable collar flashing?

 

[Mike10]

So, looking at this again in a bit more detail - would it be fair to say it's fundamentally a design issue here?

The pipes come out of the bathroom too low / roof is too high. End result being the bath & toilet waste pipes having to go through the flashing. Which in turn means where these pipes meet the roof, it's the connector elbows that go though the waterproof layer, not a straight section that could be sealed with a suitable collar flashing?

I would say that is a fair assessment.
The fact that he hasn't bothered to connect two pieces of clearly visible pipe could give a further clue to the quality of workmanship.

 

[Nige F]

Shame the bit of stench pipe through the roof isn't actually connected to the rest of it though.

Or flashed where it goes through the tiles. Maybe because they are difficult to remove with that cement bedding - And an obscure type ?

 

[jagillham]

To save doing yet another thread for this house, will continue on here...

So the area of damp on the wall I think is due to the tiles (and/or guttering) on the main roof. From the ground it looks like the guttering stops short, which then is allowing rain to flow off the roof, down the outside of the vertical guttering pipe, and ultimately dropping off down the extension wall when the pipe changes direction. However, up at roof level it does not seem to be obviously short?

I can see it's a bodge clearly, but I could do with some guidance on what exactly the problem is, and what it would take to put it right. Any rough idea of cost would be really helpful too. Given the height I don't know if this is going to be a ladder or scaffolding job etc.

Thank you in advance for any help!