Instead of felt I have black plastic under my roof.

[Jazz755]

I have really bad damp in my house. I figured there was a leak in my roof as there are watermarks on the ceiling. However I have been told that it is caused by condensation as I do not have any felt but just a plastic sheet. The roofers I had over said I have no option but to re roof together rid of the material and put felt in.
Is there anything else I can do to ventilate the roof the doesn't mean I would need to re roof?

Thanks

 

[freddiemercurystwin]

WHOA!!! Do not employ these roofers under any circumstances!!! Firstly have you actually been up into your loft to look at what's beneath the tiles? That's the first thing to do and then report back.

If you have damp all over your house that does point towards condensation for which there are lots of things to try before embarking on something so drastic.

You may like to consider having a read through the forum , start here: //www.diynot.com/wiki/building:condensation_in_houses and then do a search on condensation //search.diynot.com/forum_sear...since=any&forum_id=13&hasimage=0&topiclimit=0

Once you have had a read up you will need to post back with any observations and relevant information ie type of house: old or new, solid walls or cavity, double or single glazing, existing ventilation: ie trickle vents in the windows for instance or extractors in the bathroom? insulation in the loft if so how much? Importantly where is it damp in your house: upstairs or downstairs top of walls around windows or what? etc etc

Furthermore even if you had a plastic sheeting working as an underlay beneath your tiles provided the eaves are ventilated then any condensation problems can be cured without having to re-roof. Assuming a leak has been ruled out you will need to ascertain whether the roof has any existing ventilation and if it has is it blocked up, maybe its a bit blocked by the insulation.

To reiterate though in the first instance do not employ this roofer under any circumstances.

 

[Jazz755]

Thanks very much, so much appreciated I will get in the roof at the weekend and let you know my findings thanks.

 

[Nige F]

Sounds like you got a Dale Farm roofer - plenty of them about

 

[JohnD]

see also //www.diynot.com/forums/viewtopic.php?t=160032

 

[Jazz755]

Ok so I have been into the loft and there are no vents at the eaves only small joins and only at the front of the house, some of which where covered by insulation but I have now removed it and they are not covered by insulation. The roofers did say that the plastic was not a breathable material and there was no where for the hot air to escape hence the mass condensation. There is also a normal amount of insulation in the loft.

I have read through common causes of condensation and do not believe any of them are the cause as such. The bathroom in the house is downstairs and at the very back of the house, it is single storey (flat roof) and has 3 external walls with two large windows and a ventilator. The tumble dryer is also in a lean-too and so should not be affecting the main roof. Upstairs I have a boiler but it is ventilated directly outside and does not go into the roof. I do however suffer badly with condensation on the windows and have been told this is because the double glazing is of an older standard and the windows don't have vents.

The house is late victorian, so I am guessing the walls are solid. It is pebble dashed but in much need of being replastered as its falling off and obviously needs new windows (as above). I relise that the pebble can be another cause of the damp but the worst damp is in the center of the house, upstairs. The worst room which lead me to worry about the roof, has no external walls and the wall with the worst damp is attached to next door (its a terrace house, I have checked and they do not have an issue with damp) Also on the ceiling above the suspicious wall there are water stains (around where a chimney used to be). The main damp in the room actually starts at the floor level in the upstairs room but also runs along the ceiling. the ceiling has not got damp only at the edges but is covered in wallpaper. there are also patches around the windows. I have had a dehumidfier in the loft all week so there is little other clues with the condensation itself.

Also the front downstairs room in the house I am very concerned about the damp as it STINKS but there is definately no visible damp and so assume it has to be hiding up the chimney. I have no idea what to do about this but assume this is a seperate issue all together?

So I am assuming that I need to ventilate the roof?
Thanks for your help I Really appreciate your feedback

Thanks

Jasmine

 

[catlad]

That roofing membrane is obsolete now due to condensation problems. Yes you need to add vents, you can get some plastic over flow pipe 22mm from wicks or b&q cut it up into 6" pieces and stick them in between the overlaps in the felt pegs will hold them in place. Its a cheap diy job.

 

[freddiemercurystwin]

Aye what catlad said, make sure you add plenty each side, you can literally never have too much ventilation in a loft. Your lack of trickle vents in the windows will not be helping either, consider retrofitting trickle vents to the heads of the windows unless you plan on replacing them soon. Otherwise you need to start opening the windows more. Getting rid of condensation in a dwelling can be a slow process unless you chuck ££££'s at it so you will have to try these measures and then come back.

I wouldn't be surprised if some air bricks have been covered over in the past.

 

[WabbitPoo]

I was in a loft yesterday, adding loft insulation, and the previous tenants had used it to grow weed on a semi-industrial scale, so the entire loft was tightly lined with foiled bubble wrap, with polythene sheet on each gable end. You think YOU have a moisture problem!

Needless to say I took it down...