We use cookies to provide you with a better experience. If you continue to use this site, we'll assume you're happy with this. Alternatively, click here to find out how to manage these cookies

hide cookie message
Contact Forum Editor

Send an email to our Forum Editor:


PLEASE NOTE: Your name is used only to let the Forum Editor know who sent the message. Both your name and email address will not be used for any other purpose.

Speakers Corner


It's free to register, to post a question or to start / join a discussion


 

loft insulation


rickf
Resolved

Likes # 0

Hi, Can I simply just lay new insulation over the old ones? This would make them job quicker and less having to inhale dust from the dirty, almost blackened old layer.

Like this post
john bunyan

Likes # 0

That is what the "free" installer did with me. I wanted to keep some storage space so arranged to screw some additional height to the rafters ad installed some loft boards above the extra insulation.

Like this post
Diemmess

Likes # 0

Yes layer can be laid on layer if mineral wool.

A very real danger applies if the build-up exceeds the depth of the ceiling joists. If a surplus of mineral wool is above the joist height over a large area and covered by boards, it can and will push the ceiling down!

Like this post
rickf

Likes # 0

Thanks guys. Much appreciated info.

Like this post  
spuds

Likes # 0

Perhaps worth thinking about?.

I believe the government subsidy scheme is due to end this month or very shortly. If you or someone else in the home 'fits the criteria', then you can get this done for free.

Be warned though about the approved company you might select, some are very fussy about anything in the attic, which may hinder their speed and bonus!.

Like this post
fourm member

Likes # 0

spuds

'some are very fussy about anything in the attic'

I read something the other day about the No 10 'nudge unit'. It was realised that people weren't taking up the insulation schemes because they didn't want the bother of clearing out the loft. So the 'nudge' was to get the insulation companies to offer a 'clear out and get rid' service at a reasonable cost. That increased the uptake considerably.

Like this post
oresome

Likes # 0

On a practical note, new insulation should be laid at right angles to the existing insulation to avoid any matching gaps where the roll widths meet.

This poses a problem in that a new roll, due to it's diameter, cannot be unrolled under the lower part of the A trusses and if rolled out first in a place nearer the apex, will not then slide over the top of existing insulation to get it into it's final position.

I eventually gave up on the cross laying technique and followed the same line as the original. The rolls were cut down to match the width between the trusses and layed tightly together avoiding any gaps. The process was then much easier.

A solution to the cross laying problem would have been to lay a film of polythene first for the insulation to slide on, but I didn't have any sufficiently sized.

Don't under-estimate the effort involved. It's hot dirty work, made worse by wearing a mask and goggles and the rolls are heavy and ours were a tight fit through the loft hatch, having first man-handled them through the house and upstairs from the garage where they were stored after delivery.

Like this post
Forum Editor

Likes # 0

"This poses a problem in that a new roll, due to it's diameter, cannot be unrolled under the lower part of the A trusses"

It's worth pointing out that insulation should never be fitted so tightly that it completely blocks the natural air flow into the loft space via the eaves.

It's essential that there is air movement in a loft, as a complete lack of movement, coupled with moisture that might seep in via a cracked tile or leaking valley can ultimately lead to dry rot in the roof timbers. Dry rot (contrary to what you might think) needs two things to thrive - a steady supply of moisture and still air. Without those two ingredients it can't establish and spread.

Like this post
Graham*

Likes # 0

'pointing pit' -)

Like this post
Forum Editor

Likes # 0

Graham*

Thank you eagle eyes - typo now corrected.

Like this post
oresome

Likes # 0

When we purchased the house we live in some thirty years ago, it was only 12 months old. On inspecting the loft, I was surprised to find black mould developing on the roof timbers.

The reason for this was a lack of ventilation, the moisture content in a new house and a central heating system that vented to an expansion tank in the loft.

The builders were called back and they replaced one of the ridge tiles with a ventilation type and cut a hole in the roofing felt. This cured the problem, the mould disappearing within a few months and no further problems in the following thirty years.

Like this post

Reply to this topic

This thread has been locked.



IDG UK Sites

Best Christmas 2014 UK tech deals, Boxing Day 2014 UK tech deals & January sales 2015 UK tech...

IDG UK Sites

Apple's 2014 highlights: the most significant Apple news of 2014

IDG UK Sites

See the festive spots creative companies have released for Christmas

IDG UK Sites

Ultimate iOS 8 Tips: 35 awesome and advanced tips for using iOS 8 on iPhone and iPad