Loft conversion issues

[Castleirwell]

We are currently having our loft converted and are nearing the end of the project. There are a number of issues still outstanding, which have been resolved for the most part by the loft company.
Building regs are happy with their side of things. However, we're getting awful draughts in various places and am getting slightly fobbed off by the builders. To my mind, surely there shouldn't be noticeable draughts coming from under the window, under the floors, under the Juliette balcony doors.....

I expect some air flow / draught coming from the eves through the cupboard door... but not all the other places....

I'd like a independent appraisal. My question is, who can I get to check the works carried out?

 

[bobasd]

you can get a RICS surveor.
or a an Expert Witness Surveyor - typicly a RICS surveyor who specilises in building disputes that might be going to or could end up in court.
talk to them briefly an ask about their costs.

the eaves cupboard door should also be draft proofed.

 

[Castleirwell]

Thanks for your reply bobasd!
I spoke to a friend of a friend, who has been in the Loft conversion game for 25+ years and explained my concerns.

1) Draughts - he says these are normal as it's the air flow between floor joists and is required in order to ensure proper ventilation and prevent problems with condensation/damp etc. He does think the 100mm Celotex insulation between roof joists, covered with 25mm celetex over roof joists seems a bit on the low side? This has then been covered with plaster board and skimmed.

2) This led onto the fact the builders haven't used chicken wire to support the rockwool insulation in between the floor joists. It's simply been laid and is resting on the old ceiling joists/laven plaster. He mentioned fire risk!?! This has me somewhat concerned to say the least!

3) He also stated if using a private Building Regs company (recommended by builder) they are in effect working for the builder!! Even though I've paid for their services.... is this right?!?

Any thoughts/experiences/anecdotal evidence much appreciated....


Thanks in advance.

 

[bobasd]

you originally asked for advice on an "independant appraisal" now you've turned to someone who claims
25+ years loft experience but seems to have left you with even more questions?
get a professional in as i advised anbove.

 

[Ian H]

The only draft in our loft is through the vents in the windows.

The actual room is like an insulated box within the roof. There’s 100mm between the rafters, then 50mm across the underside of them, then plasterboard and skim.

The area outside of the box (300m at the back, 1000mm at the front and 50mm over the top is all drafty.

The insulation stops the warm inside meeting the cold outside and the draft deals with any moisture that ever finds it way in there.

There is no draft under the floor and no chicken wire.

 

[cdbe]

When I did mine, chicken wire and mineral insulation were to fireproof the floor instead of double boarding the ceilings below.

 

[wwwebber]

There is no draft under the floor and no chicken wire.

Hi, how did you achieve this ?, is the floor simply insulated with mineral wool ? or are the floor voids sealed off from the eves ? or both ?

Cheers.

 

[Ian H]

Floor void is sealed off with the RSJ’s that hold the floor up/walls are built on and the rest has acoustic wool stuff as you normally would. Between and over the joists in the void outside the room and just between the floor and bedroom celings under the room bit.

 

[JP_]

Drafts are so 19th Century. There should be no drafts. That would defy the point of insulating. Trickle vents yes, extractor fans yes, drafts no.

 

[Leofric]

Private building control firms, local authority or NHBC building control all work to the same building regulations ,although NHBC have their own additional Standards which they use, and they should all be impartial enforcing the regs.
As DIY says there should be no draughts; in fact there are rules on air penetration and limiting infiltration ( why are building control happy with their side of things if you are getting draughts from under windows, floors and balcony doors !!!).
The ventilation of the room should be controllable by trickle vents (background ventilation) and opening windows (purge or background ventilation) .
Ventilation of the air space on the cold side of the insulation is to reduce the risk of condensation but that should not enter the room as draughts ,as others have explained.
Others have already advised on an independent appraisal but why not speak to building control or the person who drew the plans for the bldg. regs application and mention the problems first ?

 

[Castleirwell]

The only draft in our loft is through the vents in the windows.

Thanks for the reply... so the only draught "should" be through the window vents... Unfortunately this is not the case.
There's noticeable air flow coming from each and every spotlight. And the draught coming down the stairs/hall from loft to 1st floor landing often feels like a window may be open in either of the loft rooms.... but all window's are closed.

The actual room is like an insulated box within the roof. There’s 100mm between the rafters, then 50mm across the underside of them, then plasterboard and skim.

They used 25mm across/over the 100mm insulation and ceiling joists

The area outside of the box (300m at the back, 1000mm at the front and 50mm over the top is all drafty.

Understand the air flow gap over the top of the flat roof needs to be 50mm (I think they've only done 25mm) Don't quite understand or see how I'd measure/check the front and back? Excuse my lack of knowledge

The insulation stops the warm inside meeting the cold outside and the draft deals with any moisture that ever finds it way in there.

Indeed and if too much warm air escapes through the "vents" where the spotlights are, and hit the cold roof, this will cause condensation

There is no draft under the floor and no chicken wire.

Unfortunately there is/was plenty of air coming in under the floor. When I mentioned this to the builder, he said once the skirting boards are put on and bathroom floor tiles go on.... there'll be no more draughts.... something doesn't sound right to me as surely there'll still be cold air penetrating under the loft floor / over the 1st floor ceiling (which has insulation over it). I've since noticed that slate (faux) tiles on the side of the L dormer have a 1-2 inch gap at the bottom and are not flush with lead flashing.... I'll post some photos

I've booked in the RICS Building Surveyor, but they aren't coming for a few weeks yet....

Question: What is the correct way to install a cold deck flat roof, with Celotex insulation and spotlights? I'm of the opinion what has been installed in not correct or adequate. Thanks in advance.

 

[Castleirwell]

Private building control firms, local authority or NHBC building control all work to the same building regulations ,although NHBC have their own additional Standards which they use, and they should all be impartial enforcing the regs.
As DIY says there should be no draughts; in fact there are rules on air penetration and limiting infiltration ( why are building control happy with their side of things if you are getting draughts from under windows, floors and balcony doors !!!).
The ventilation of the room should be controllable by trickle vents (background ventilation) and opening windows (purge or background ventilation) .
Ventilation of the air space on the cold side of the insulation is to reduce the risk of condensation but that should not enter the room as draughts ,as others have explained.
Others have already advised on an independent appraisal but why not speak to building control or the person who drew the plans for the bldg. regs application and mention the problems first ?

I've had Building Regs (private company recommended by builder) come of and check, they kind of brushed over the issue of insulation.

Now I've found out that if Building regs are the builder's company (recommendation), even if I'm paying for them, they are essentially working for the builder, which makes sense.... why else would they builder put all this business the way of this company?

 

[Castleirwell]

When I did mine, chicken wire and mineral insulation were to fireproof the floor instead of double boarding the ceilings below.

A relative carried out their own loft conversion and Building Regs stipulated the use of chicken wire on the underside of floor joists, which then have rockwoll (sp?) insulation. Apparently this somehow provides 30 mins of fire proofing?

 

[JP_]

IMO, not an expert, it should all be sealed up somehow. There should not be cold air flowing below your floors. Yes, if it was still a loft you'd have ventilation, but it's now a habitable space.
What did they do with all the insulation that was in the loft? When I had my loft conversion done, all the insulation was used under the new floors for both sound and thermal insulation. That would also stop any excessive drafts if air was getting in through soffits etc.

Pics, all piled up while they worked, then put back after.

 

[geraldthehamster]

No, there shouldn't be draughts, in the room or under the floor. The loft room(s) and the floor between them and the storey below are part of the warm, insulated envelope of the house. Ventilation to the rafters should be the other side of the vapour barrier.