PITCHED ROOF EXTENSION - WATER COMING IN!

oakenlivery

We are having a problem with a pitched roof extension to a main building. The house is a 1910 end of terrace. The extension, which used to serve as an old outside lavatory and kitchen, has a pitched roof with interlocking double channel profile tiles. After replacing the kitchen door with a U.P.V.C. type, my wife noticed that whenever we had rain, damp patches appeared on the newly plastered junctions between ceiling and walls immediately above the hinged side of the new door.

I called back the door fitter to look into the problem. He has told me that it is a roof problem which has always been there and is probably the reason why the old hardwood door frame was rotten in the first place. It was unnoticed in the past due to a wall unit covering the area and on further inspection of the internal roof timbers I can see residue of watermarks so I guess he may be correct.

I have now looked outside at the junction between extension roof and main house. There is lead flashing which is step chased and mortared into the main house brickwork. This lead flashing runs down and is dressed over the abutting tiles. When I pulled back the lead to inspect what is going on underneath. I was surprised to see that the tile just ends about 10 - 15mm from the wall with no sign of anything coming up from below. Shouldn't there be a metal soaker fitted against wall beneath the tile or at least some roofing felt dressed up the wall. I would expect something in there to catch rainwater which may be forced in either by wind pressure and/or capillary action.

Any advice would be most helpful. Thank You.

alastairreid · Posted: Tue Nov 03, 2009 4:01 pm Post Subject:

there should be soakers or a secret gutter beneath the tiles.

sounds like the waters tracking back under the apron.

1st thing to do is strip the tiles back to see whats there.

HaydnExport · Posted: Wed Nov 04, 2009 3:13 pm Post Subject:

you dont put soakers under tiles you dress them over each tile, from what your saying the cover flashing and soakers are one piece? As alastair mentioned a secret gutter would be best , and then renew the cover flashing.

oakenlivery

Much appreciated. How and with what do you form a secret gutter?

alastairreid · Posted: Wed Nov 04, 2009 7:09 pm Post Subject:

clicky

datarebal · Posted: Wed Nov 04, 2009 10:00 pm Post Subject:

They are profiled interlocking tiles, you dont need soakers just a cover flashing that obviously is dressed over the rolls of the tile.
Felt should be turned up the wall.
The flashing should do the weathering..

Look again for damaged tiles.

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alastairreid · Posted: Wed Nov 04, 2009 11:27 pm Post Subject:

ha, missed the profiled bit!

make sure the apron goes all the way over the profile as well.

HaydnExport · Posted: Thu Nov 05, 2009 4:41 pm Post Subject:

I'd recommend soakers of a secret gutter, just dressing the cover flashing is asking for trouble.

datarebal · Posted: Fri Nov 06, 2009 8:11 am Post Subject:

A cover flashing over interlocking profiled tiles is perfectly exceptable done correctly the no risk at all
"you dont put soakers under tiles you dress them over each tile"
in fact, no different than the above incorrect comment. (we are talking interlocking single lap tiles not double lap tiles or slate.

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