Attic Needing More Ventilation?

[lhaigh]

Hi I am a tenant living in what I would describe as a poor condition property. Its a terraced 2 bed house built between 1920 and 1940. It has drafts, leaky gutters, damp walls, holes in walls where slugs are entering (I have had to put blu tack in the holes while the landlord decides what to do about them), peeling wallpaper, had to have work done on the chimpey as corners of the chimney were falling off, and now mould and cracks on ceilings upstairs. the roof is gable and our top floor is up in the attic slightly so the ceilings are flat then sloped. had a roofer round yesterday after asking for about 4 weeks who stood in the garden looked at the back of the house and said roof was fine, didnt look in the attic, took one look at the ceilings and said condensation even though i have good ventilation in the house and a constant temperature so the house isnt getting hot then cold. he said we need some roof vent tiles in the attic as there isnt enough ventilation up there. My other half was annoyed that he didnt look in the attic so he had a look himself. it looks like 20mm of loft insulation was put in in 2009 on top of 20mm of old insulation which could have been there 20 odd years so we dont know if theres a vapour barrier. there was big chunks of mortar falling down from the roof on top of him when he went up there (only popped his head in as we dont have any boards) and the chunks that came away crumbled between our fingers. and the roof is constructed in a way that you have beams of wood going across with what looks like slate tiles glued on with mortar so you can see the back of the tiles. my question is, is it going to be possible for someone to put these tiles in without the other tiles falling off and how long is it likely to take and at what cost? house is 40m squared. im just trying to ascertain whether my landlord will have this work done as everything they have done is a bodge job and i am considering getting environmental health involved now. im convinced when they actually bother to look in the attic that they will probably find more crumbly mortar and tiles and possibly even damp wood and insulation. can anyone give me any advice?

thanks

[Old_Geezer]

Paragraphs make for easier reading (and an incentive to do so).

A roofer would have more expertise than I but it the house is full of holes as you describe I'd have thought more ventilation wasn't the issue.

As far as I am aware it matters little how old insulation is as long as it still insulates, and putting new on top of existing isn't unusual. I really don't see a barrier to the loft as being the issue. Many folk have insulation in the loft without issue. And lofts are not renowned for being airtight.

Chunks of mortar falling down confirms the place is badly in need of maintenance. I'm not getting a great feeling about the roofer you got in. Without a proper inspection it would be difficult to say if it is repairable or needs replacing. I'd suspect the latter. Were you the owner I'd suggest getting a few more inspections/opinions/estimates for fixing it. As a tenant I'm wondering if your best bet wouldn't be to find adequate housing and a decent landlord.

[buildersmate]

Good answer, OG.
To add, roofs should never have a vapour barrier, neither at the ceiling level nor directly below the tiles. What was fitted under tiles for many years was felt, often black in colour, which was a barrier to water permeating upwards, but which then relied on air flowing through the roofspace to get rid of water vapour that would otherwise condense in the cold loftspace.
Nowadays breathable membranes are very common that don't need ventilation because they allow water vapour to pass through.
You don't have either of these.

Slates are conventionally nailed onto horizontal battens and it sounds like you have a very old roof system have the slates are mortared in place. I would have no confidence in what is being proposed.

40mm depth of insulation is downright feeble and you need at least 250mm depth in there, and ideally more. To give an indication, I have the equivalent of 500mm of fibreglass in my property. This alone will raise the temperature around the celing area and reduce condensation inside the living-space.

[lhaigh]

thankyou for your replies both. I have my 3 year old in at doctors this aft as I think shes getting asthma now. have just discovered my landlords havent protected my deposit and ive got shelter and the council on my side so i think its time to call environmental health in.

[lhaigh]

I'm sorry that should say 200mm of insulation so I have 400 on total. Does that make a difference?

[The Builder]

If you can see the underside of the slates, then there is clearly no sarking felt, (as it's called). With no felt, you certainly don't need further ventilation.

On your ceilings, I guess the signs of condensation are on the slopey bits. The flat part has 400mm ....... that's fine. I'll bet the sloping ceilings have no insulation at all (very common back then.) Of course there's no way of getting any insulation in there. The ideal solution is to plant insulation of the board type (Celotex, Kingspan) onto the sloping parts, then plasterboard and skim. It doesn't sound as though the owners would be willing to pay for this though.

The mortar on the underside of the slates is possibly a previous "bodge" to try to prevent slates slipping. They obviously have "nail sickness" ie the nails have rusted and are no longer holding the slates.

Here, the ideal is to strip the whole roof, lay breathable felt, new battens, and re-nail or renew the slates.

Environmental health would certainly add weight to your position.
Good luck.

[lhaigh]

Thanks. We had another look properly just now and found parts of the roof with 200mm more insulation than others, gaps between tiles, crumbled mortar everywhere, possible mold and water damage to tiles and wood, loose bricks and bricks with no mortar, and what actually looks like a beam or joist across the length of our room being propped up by 2 bricks at each end stood on their ends covered in mortar like they've been used once before somewhere else. Ive sent pics to the council!

[lhaigh]

Oh and to add the condensation is mainly on slopey bits but also along the flat ceiling where it meets the wall. Here's hoping the council will inspect properly and soon! :/

[lhaigh]

Just been told by the roofer that hes putting vent tiles in today. i dont know how many or where, but he wont go in the attic even though ive told him about what weve found up there.
He said oh dont worry the slates will be nailed on anyway so that fine its normal. he told me this whilst he was still on the way round to my house! Think youre right and environmental health will have to come and have a look now.
Is this likely to make the damp ceiling problem worse and my house even colder? (already felt freezing in the attic anyway)

thanks all for your help

[The Builder]

For the main part of the ceiling, the vents will be above the insulation, so no problem with that.
With the lack of insulation in the sloping ceiling, I don't think it would make it worse either. Using the flat part of the ceiling as access (up in the roof void that is), it might be possible either to have a specialist firm "blow" insulation into the sloping void........ or at least poke regular glasswool insulation down into the void