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Loft Insulation Options

S-Man

S-Man

StrivingON
Just evaluatiing options to increase the amount of loft insulation we have.

We currently have the legacy 4" of fiberglass wadding between the rafters. The centre part of the loft, approx 40% of the floor area is boarded with chipboard panels.

Seems like the current legislation specifies 12" of insulation and another 200mm of e.g. Knauf Eko Roll would do the job for the 60% that is not boarded.

But what to do with the boarded bit?
... there seem to be some options to raise the floor like this:
www.loftzone.co.uk
Hope I could get a loft ladder to work with the increased floor height this results in.

And what about the newer insulation types like this:
https://www.superfoil.co.uk/suspended-floor-applications/

Any suggestions to make the job easier and meet current regs?
 
The current regs don't apply to existing installations, as you know.
If you still want to improve things I'd insulate the uncovered bits as you say and ignore the boarded bit. If you really wanted to you could add polystyrene to the boards and board it again with some OSB. You won't walk on it that much. Equally, you could decide which bits of the loft you want to store crap on and then sling fibreglass over the boarded bits that you don't need to be boarded. Raising the floor sounds like a lot of work for not much return. Sure, you can do it, I've boarded a loft and made noggins to hold boards, but it#s a bit of a labour of love.
 
Actually I didn't know - sort of. But I think it only matters if we want to sell the house and then it loses brownie points for the legacy insulation.


Good points, well made Steve! Thanks.


And how did you know that we are only storing crap up there? :D
 
For the boarded section pull up the boards and replace the existing with PIR insulation board from Celotex to the max depth you can get without stopping the boards going back down. This is about double the thermal value of standard insulation for the same thickness so 100mm PIR = 200mm of standard. Otherwise use the additional 200mm on non boarded areas as planned. Be careful not to block any venting around the soffits.
 
When you sell the house half of the construction will be to legacy spec. Electrics, heating, insulation, probably by then windows and doors, nobody cares. If I'm spending upwards of 250k, possibly twice that and more, on a house am I going to worry about whether there are gaps in the insulation that I can fix for a couple of hundred at B&A and an afternoon's labour? Hardly.
 
i like to put my loft to purposeful use at low cost of course. Perhaps a hornet farm? or breeding woodpeckers?
 
Good Afternoon All,

As noted above you don't have to put more insulation in but it would improve the insulation value if you did and improve any future EPC. Yes adding another 200mm to the accessible bits is simple to achieve. It does, potentially, get a bit labour intensive after that. I wouldn't rip up the existing boarding just overlay with PIR and some OSB so you can still store stuff.

I'm not sure about the 'nobody cares' bit moving forward as house assessing will likely change if such as PAS 2035 comes to pass???? Certainly there is little sense in carrying out some improvements if they aren't cost effective.

Regards

Richard
 
Is there an insulation board with a OSB top layer that can just be put straight down?

I’d love to do mine, but would prefer a one fit product, if possible..!

And what about the ancient loft hatch? (12mm ply opening straight up into the loft space) surely doing all new loft insulation is uttterly pointless if you don’t change this to one that seals fully?
 
Something to think about is not covering the electrical cables as they will not be serviceable after, also be careful with with burying cables in insulation as it can lead to overload and other issues especially electric shower supplies. Don't cover junction boxes either as they need to be checked.
 
Rug Doc said:
Is there an insulation board with a OSB top layer that can just be put straight down?

I’d love to do mine, but would prefer a one fit product, if possible..!
Click to expand...

There are soffit insulation products out there that have a PIR insulant bonded to cement particle board. You could use the same, turned-upside down it'll stand light traffic/ storage no problem. Have a search - you can find kingspan sell several variants of PIR faced with 6mm plywood, for example. But not cheap, and in full sheet (1220 x 2440mm, 100mm of PIR) size, will run you about £45/sq.m...

Other wise about 6mm of very cheapest ply or mdf is about all you need to avoid damage in such a loft use; any PIR insulation board has far more than enough bearing strength to shrug off the loading once point impacts are covered. Even hardboard would do.
 
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Darren L said:
Have you looked at Superfoil insulation or the sprayed on types?
Click to expand...

Good question - a quick response:

The foil types are ...all problematic. They do not perform anywhere near as well as the notional U-value claimed (often using a non-standard test method to give the claimed Lambda value that results in the consequent 'U') These types are also ...notably flammable; and expensive!

Spray -on foam - I'm very, very wary of that. messy, and once done cannot be revisited / re-fixed, puts roof timbers beyond inspection; and the sealed surface in the wrong place could mean trapping-in moisture around roof timbers (interstitial condensation problems if used applied from above to a ceiling- its quite a different condition in that regard to applying from the inside of a wall to studs for boring reasons there isn't space to go into here.) And - not cheap.
 
S-Man said:
And how did you know that we are only storing crap up there? :D
Click to expand...

Are you not on main drainage? :D

Similar situation here, except that I've boarded out the entire area as there's always too much crap for the available space. However, most is carpeted with at least 3 old ones. It prob. wouldn't pass an EPC inspection but height restrictions mean that I wasn't able to add height to the existing joists.

These energy hike do concentrate the mind, don't they?;)
 
Funnily enough this came about because my daughter's partner asked if I would help him to add some extra insulation to their loft - which is in the same situation as mine.

I had hoped that the effluent in my loft would be reduced as some of it flowed to theirs! ;)
 
Darren L said:
Have you looked at Superfoil insulation or the sprayed on types?
Click to expand...
Sprayed on foam insulation will render your property unmorgageable should you wish to sell in the future, plus as mentioned make roofing or timber/rot issues difficult to diagnose to say the least .
 
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