Mushrooms on walls !!!

UPDATE:

I think the 'shrooms are "cellar cup" (not sure if it was mentioned in this thread). We've sprouted a lot more since then.

The roofer (not knowing any, it was the worst possible approach to try the Yellow pages) had a look and diagnosed some loose flashing. Relocated, put a screw in and left.

Now the side of the house we are talking about (front) has a canopy (storm porch) which extends 4'. Not *quite* sure how it fixes to the house, however, I was working in the room on Monday - it was chucking it down, when I heard a "drip ... drip". Quickly discovered water was coming from somewhere around the windowsill. Went outside and saw the external wall underneath the canopy was wet. This is the outside of the wall which has the shrooms in.

Now I don't think that's a coincidence with the first problem.

I have just been into the loft (which is a pig of crawling) and the insulation above the area where the 'shrooms were growing is wet. So that is a roof leaking, somewhere. It can't have been long, as the timbers haven't rotted, or gone spongy.

Can anyone suggest a single problem which can cause a leaky roof, and water to seep down the wall below the canopy ?

Since this problem has only recently occurred, would it be a reasonable hope that the damage done is minimal.

Called the roofer for a thorough quote. He was due to confirm an appointment on Tuesday, but (as is my experience with tradesmen :( ) not a squeak. So I'll have to try another.

Re the valleys, all you can dd is ensure that no moss etc has formed a dam somewhere causing the water to back up and overflow. Also check there are no cracks in the lead valleys. If they have been put in in a continous run expansion and contraction will evantuall cause the metal to work harden and crack. They should be installed in 2m lengths so forming expansion "overlaps", Esp. on the South side where they catch the sun.

It's possible to do tricks with flashband or expading foam or silcon but such cures don't last.

If the roof is not very steep or if it is very large catchment , the valley lead (depending on what sort of valley it is) might need to be very wide and it isn't. Replacing it is a big job.

Depending on the condition of the roof, the time might have come to consider replacing the lot making sure you get a proper job. Not cheap.

Re the rot, sounds like wet rot which goes away when the moisture source is removed. However dry rot often follows (may already be present) which can spread through the whole house even after the moisture source is removed In any event when the leak is sorted, the timber needs treatment.

This needs urgently fixing as Winter appraoches.

Some sort of temporary repair and a permanent fix next year when the weather improves?

Water from leaky roofs can appear in many unexpected places. Often runs down the void in cavity walls and appears much lower down.

We had the valleys re-flashed 2 years ago, exactly as you describe. They're completely free of any moss.

It is a shallow roof.

Well the loft is dry (expect below the leak) and the timbers seem sound. I have a ready stack of replacement tiles I acquired from a renovation supplier a few years ago.

So the dampness I see on the outside wall could actually be a result of the leaking roof, rather than anything to do with the canopy attachment ?

Thanks for replying - still have to call a complete unknown to have a look, but it's good to feel less in the dark.