Flashing problem?

[m0t]

Following from my thread here:

//www.diynot.com/forums/viewtopic.php?t=166949

I have had a brief check of the roof flashing (where the tiles meet the wall), wondering if it could be the source of the water ingress.

The roof is tiled, with the tiles approx 1cm thick and where each tile drops on to the next and the flashing runs over it there is a gap as the flashing goes diaganally over the step rather than hugging the tiles.

The gap is big enough to fit my finger through and I can feel the blockwork behind it. Theres also a load of muck under there. I have drawn a (poor) picture to illustrate what I mean. Is this the correct way the flashing should have been installed? Would sealing the (large) gaps with silicone work or does it need to be completely replaced?

I can inspect the bottom of the wall the flashing butts to from the garage and it has a lot of wetness in it (we started noticing this a few months back but blamed it on a broken tile that we replaced, although this hasn't made a difference).

 

[DAZB]

It is quite possible that if it is prone to driving rain on that face then yes it could be blowing in.Also the fact that you can reach the blockwork with your finger tells me that there is not enough cover . You could try dressing the lead down and beating it into shape to suit the tile profile but if you have not done it before you may just be better sealing the gaps with something like this :

http://www.tool-net.co.uk/p-324031/everbuild-everflex-lead-mate-sealant-lead-grey-310ml.html

 

[m0t]

Here is a picture of the flashing down:

http://www.btinternet.com/~tom.garrett1/05022009034.jpg

I lifted the flashing up to take a photo, this is not the part of the wall where the problem is (I can't reach that from inside), but even at this point parts of the tile seem wet up to the edge.

http://www.btinternet.com/~tom.garrett1/05022009037.jpg

The problem may have become worse over the last few days becasue of the snow, but the bottom of the wall has been wet for some time, so it isn't exclusively snow related.

 

[justlead1]

Hi. I would like to help but images need to be more of an overview to get a idea of the situation.

 

[noseall]

those images are of no use at all.

are the tiles profiled, i.e. concrete interlocking as opposed to plain flats?

soakers?

i am of the opinion that even some (non-profiled, marley moderns, cut wessex, etc.) concrete interlocking tiles need a soaker also.

 

[m0t]

The tiles are profiled and look like the ones called '49' on this page:

http://www.centralroofingsupplies.com/products/pitched/tiles/concrete.html

I can't really ge a better picture of the roof at the moment due to the weather.

 

[noseall]

as long as there is part of the tile upstand profile, covered beneath the lead, then water will not run in or splash in.

it is true to say however, that a build up of snow, in vulnerable areas, behaves quite differently to rainwater.

i remember water in a lift causing a conundrum. what was happening was, as the lift descended it sucked air in through a cluster of tile vents directly above the shaft. as snow had built up around the vents, some was being sucked into the lift shaft.

 

[m0t]

I believe I've cracked the problem!

The flashing covers up to the first ridge on the tile, but in the position where the wetness is the flashing is sitting about 5mm above the tile.

There is a gutter from the roof above that drains onto this tile, and the water runs onto the ridge that the flashing is sitting on, half of it is running off the ridge into the trough of the tile, and the other half is running backwards under the flashing against the wall and into the roof space.

Now my plan was to wait until it is dry and use some silicone sealant to secure this bit of flashing to the roof, and also extend the downpipe of the gutter out slightly so it drains further onto the roof. Does this sound like a good plan?

 

[noseall]

Now my plan was to wait until it is dry and use some silicone sealant to secure this bit of flashing to the roof, and also extend the downpipe of the gutter out slightly so it drains further onto the roof. Does this sound like a good plan?

sounds like a plan to me!