Lots of condensation on inside of new roof membrane

Just found these, has anyone used them and is there any reason that they wouldn't work? A bit expensive, but much cheaper than paying someone and I could fit them.

http://www.ebay.co.uk/itm/EasyVent-...hash=item3d2ba97b7a:m:mCPiRI6dsAg35b-Hdi4lK_Q

 

There are two fireplaces downstairs back to back, both are boarded up, it used to be a backboiler. There's nothing inside the chimney apart from a silver metal ducting pipe and rubble from the removal of the chimney stack on the roof. The rest of the stack is still in the loft below roof level and I'll be removing that when I get some time to do it.

 

Quick update on this. So I ordered some of those vents I linked to and put them in on Sunday. I just fitted them and left the water where it was and then on Monday, checked it again and there was a noticable imporvement in areas where the membrane wasn't absolutely sodden. So I went up again with a load of kitchen roll and properly dried the bits I could reach and I've just been up now and those area are bone dry still, so I think we are on the right track.

The original roofer got back to me and said he's never heard of this happening, but he can supply some plastic vented tiles for £20 each and we will need 8 and I think he will fit them for free, but he is really not having it that poor ventilation is causing it, for some reason. The other thing that he said is that he will need to cut holes in the membrane to fit these tiles and it will then not be watertight if water gets under the tiles. I think I may just buy another 25 of these lap vents.

Chimney coming out tomorrow and once that's out, I can get all the insulation out and renew that.

 

In Salford, it's been below zero a couple of nights since the vents have been fitted, but much milder today. I've removed about a quarter of the chimney tonight, it's made from really heavy, grey bricks that are killing me taking up and down the loft ladder in bags.

What I was meaning about there being good progress was that the sodden parts with droplets all over that I didn't dry are still there, so I think that it must reach a point where it just can't breathe at all. The rest is still dry for now at least, so fingers crossed.

I'll update when I know more, cheers for the replies!

 

Thanks, No, I haven't done any tests. I am wearing a proper 3m mask with particulate filters on. It is coming apart quite easily and is already quite damp because of the condensation up there. The house is full of asbestos though, 1950s council house, asbestos ceilings, under the stairs, soffits, drainpipes etc a lot of which has now gone. Can you tell from a photo if it looks like asbestos bricks?

 

They look like the cinderblock used on the inside walls of the house but bigger and heavier.

The condensation is dispersing quite quickly now in the areas I haven't mopped, probably due to the milder weather, but it's good to see it is escaping now.

This is yesterday's progress, had to abandon as the rubble sacks weren't rubble sacks, but back on it today.