Help with lead valley please.

[Floppy1234]

Hello,Excuse my lack of terminology as I am trying to address a roof issue as a novice.

The garage was a stand alone originally,a small porch has been built to walk through from my back door straight into garage.
The garage and porch roofs are both pitched and meet in a V valley,hope that makes sense.
The timber in garage underneath the valley is very wet,it has been a problem for a while but thought I would have a look as to where it's coming from.
There is a strip of lead to form the valley however there was felt underneath the lead which was soaking wet.
I have gone up on the roof today and taken off the last row of tiles either side of lead,removed lead and have removed the felt,etc back down to timber.

Now I am reading as much as possible and would like to stick with lead and hope the soaking timbers are more from the felt being laid underneath the lead directly onto timbers.
I am looking at geotec membrane to sit lead on this time,however I don,t think the lead was far enough underneath the last row of tiles.
Also the lead was laid in one long piece so I will need to cut it and overlap it.

should I buy more lead flashing so I can put more strips further under the tiles either side?
Is there a way also that I can slope the valley as I only have guttering one end of valley.Thanks in advance and if anybody has any other ideas I am open to suggestions as now I have started I would like to sort it asbestos as I can,thank you.

 

[ree]

Posting pics would definitely help us to advise you.

 

[Floppy1234]

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• Floppy1234
• 29 Oct 2014
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• Floppy1234
• 29 Oct 2014
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• Floppy1234
• 29 Oct 2014
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• Floppy1234
• 29 Oct 2014
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• Floppy1234
• 29 Oct 2014
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• Floppy1234
• 29 Oct 2014
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Hope the photos are ok as I have never posted a photo before!

 

[kbdiy]

As an amateur, my thoughts:
1) the porch roof looks to have felt under the tiles. The lower edge of this felt needs to be lifted to that it can drain into the valley (when it is repaired);
2) the original lead does not look wide enough to have sufficient lap under the tiles and thus will have allowed rain to overflow the edges and soak the timber underneath;
3) the old wet timber needs to be completely removed and replaced with new. It should be packed up to give a slope towards the gutter/drain;
4) by all means add a waterproof layer under the new lead and make sure that lead laps under the felt on the roof, both sides. Hard to give precise measurements but be quite generous especially as the garage roof is quite a shallow pitch.

Hope that is some help.

 

[Floppy1234]

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• Floppy1234
• 29 Oct 2014
• 1

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• Floppy1234
• 29 Oct 2014
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Yes thanks that is a great help.

I had to remove quite a lot of insulating foam from ceiling,tiles and wood,etc.NoW I can access I think the wet boards,wood to replace them.

Should I use 12 mm marine ply where I have to remove rotten boards?

The porch side of roof was in a much better condition than garage side,even majority of felt is dry under tiles.

I have nearly stripped back all of the rotten felt on garage side roof.

sO my thinking is new marine ply

Wider lead in shorter pieces,I think 450mm wide should beok as existing lead was 300 mm and that will allow for 4 inches overlapwithtiles.

Use membrane as lead was soaking wet underneath plus it had been stuck down to felt or the bitumen may have just stuck to it over the years.
I am thinking of trying to do a slightly raised fall in valley to send rainwater towards the front of the porch as the guttering is there.

Just trying to piece it all together in my mind so I have some sort of plan ,many thanks.

 

[kbdiy]

Sounds reasonable. I think the problem with felt is that it can sweat so adding to the problem of damage to the timber.

The main thing is to make sure you have good overlap between the various under layers of felt/ membrane etc and overlap onto the lead so there is no risk of water blowing back under the tiles and getting behind the underlay - otherwise you'll be back to square one in a couple of years.

 

[ree]

In pic 5.its best to remove all the clutter and show how the "valley gutter" is constructed in a posted pic.

See user: ban-all-sheds for how to correctly post pics.

Does the valley gutter slope down to the discharge point into a plastic or CI building gutter?

The lead sheet appears to be a one piece length of lead. This is too much - lead sheet should be in 1500mm lengths with a 150mm overlap. The correct width of the lead cannot be determined until the valley gutter arrangement can be seen.

Pics 7. & 8. need a context, and perhaps flash.

 

[ree]

In pic 5.its best to remove all the clutter and show how the "valley gutter" is constructed in a posted pic. If you google "box gutters" you will get an idea of how it should be.

See user name: ban-all-sheds, for how to correctly post pics.

Does the valley gutter slope down to the discharge point into a plastic or CI building gutter?

The lead sheet appears to be a one piece length of lead. This is too much - lead sheet should be in 1500mm lengths with a 150mm overlap. The correct width of the lead cannot be determined until the valley gutter arrangement can be seen.

Pics 7. & 8. need a context, and perhaps flash.