Lean to roof leak

[andyw1974]

HI everyone,

My name is Andy and I am hoping that someone could please offer some advice.
In October 2012 we had an extention done, part of this was to knock down the adjoining garage and rebuild, the rebuild consisted of a new lean to roof which I think was done to about 18 degrees. All the plans were drawn by a qualified surveyor.
Whenever we get heavy rain full parts of the internal walls get damp and we get circular looking damp patches on the internal plastered wall. In the garage there are no plaster boards just original walls that get very damp.

The builder advised the roofer to come out again a couple of times, and in the end he applied another section of lead flashing. We thought this had fixed the problem but it seems that whenever there is heavy rainfall the rain finds it way back in.

So we're not sure what we can do now, I don't have any faith in the roofer and builder we have given them every chance to resolve this. Ideally I would take legal action but that is expensive, so the other option is to try and fix myself but I am not a builder/roofer.

We need to get it sorted as it's getting the wife and me down now.
If there is anyone that can offer some advice I will be eternally grateful.

I will upload some pic shortly.

Cheers
Andy

Untitled

• andyw1974
• 16 Jan 2015
• 1

Untitled

• andyw1974
• 16 Jan 2015
• 1

Untitled

• andyw1974
• 16 Jan 2015
• 1

Untitled

• andyw1974
• 16 Jan 2015
• 1

 

[andyw1974]

Should the builder have incorporated a cavity tray before installing the lean to roof?

 

[catlad]

Why don't you move the down pipe or extend it and see if the problem goes away.

 

[andyw1974]

I was thinking of doing this, but there are still other areas that are getting damp/wet during the wet windy days.

 

[Alastairreid]

Would definitely re-route the rainwater outlet from that corner, the cill detail looks suspicious.

Should they have installed cavity trays? probably... check the perp joints in the blockwork and redo if necessary.

Check the gutters above the extension are clear and not spilling back into the cavity.

As a last resort the wall above the extension can be sealed with a water repellant.

It does look a tidy job.

 

[noseall]

One particular job springs to mind (similar to yours) whereby it was the windows letting in water. The silicon seal at the masonry abutment was done poorly and was allowing water to get past the outer masonry and filter down.

 

[Mw Roofline]

Noseall and catlad have got it.

 

[andyw1974]

Thanks everyone for the responses. Yes I will look at getting the walls sealed.
I will get the down pipe moved ASAP.

What is the "cill" and I don't know what perp joints are?

Would it be a good idea to apply grey flashing sealant under the lead flashing just in case the wind is forcing rain under the lead?

Thanks
Andy

Would definitely re-route the rainwater outlet from that corner, the cill detail looks suspicious.

Should they have installed cavity trays? probably... check the perp joints in the blockwork and redo if necessary.

Check the gutters above the extension are clear and not spilling back into the cavity.

As a last resort the wall above the extension can be sealed with a water repellant.

It does look a tidy job.

 

[andyw1974]

I will have a look at this. This was another area where the roofer came back and also did some more work on.

Is it the roofers responsibility to get this resolved and waterproof?

Is there a chance that if I get up there and walk on the tiles they might crack, I'm 16 st?

One particular job springs to mind (similar to yours) whereby it was the windows letting in water. The silicon seal at the masonry abutment was done poorly and was allowing water to get past the outer masonry and filter down.

 

[Alastairreid]

The window cill.

Perps are the mortar joints between the blocks.

 

[catlad]

If you climb on the roof without using something to protect the tiles then there is a good chance you will break some tiles and its not going to be the roofers responsibility if the work he did on the extension is water tight, Alistair has told you it could be coming down the cavity from the main roof.

 

[andyw1974]

There is no guttering above this extension as it's on the side of the house, which is where the leaks are happening.

If you climb on the roof without using something to protect the tiles then there is a good chance you will break some tiles and its not going to be the roofers responsibility if the work he did on the extension is water tight, Alistair has told you it could be coming down the cavity from the main roof.