Making joists deeper and boarding
Discussion
Chaps, I have rolls of 150mm space blanket (thankyou EON you pillocks), and 75mm-ish deep joists. So I need to raise those so I can fill them with one layer, then cross-lay another. Additionally, there is a boarding walk way down the centre of each span (the house is roughly H-shaped).
As simple as battens or 2x4 bashed onto the joists with some more substantial supports for the walkways, or is there anything else I should consider?
As simple as battens or 2x4 bashed onto the joists with some more substantial supports for the walkways, or is there anything else I should consider?
There's nowt up there at the moment - was the remnants of 50s glassfibre until I cleared it out. That was NOT a pleasant job.
I would have ordered 100mm, but wifey got there before me, hence the oversize "because it was on offer".... 148 rolls of the stuff!
There are airbricks on all four gable ends, and from casual inspection it looks like the eaves are currently sealed.
I would have ordered 100mm, but wifey got there before me, hence the oversize "because it was on offer".... 148 rolls of the stuff!
There are airbricks on all four gable ends, and from casual inspection it looks like the eaves are currently sealed.
Edited by RedLeicester on Tuesday 23 November 16:26
RedLeicester said:
Ah. So it is as simple as that.
Job done then!
Well, almost. You should raise the walkways with proper structural supports; probably timber towers/trays in your case if you get my drift. FWIW to others Kingspan is easier to lay and would give the same insulation for a LOT less depth.Job done then!
148 rolls!!! Buy a proper mask and overalls and good luck.
Yep the walkways I'll be doing with rather bigger bits of timber.
Kingspan is the final plan, but right now we are part way through ripping out all the plumbing and leccy, and slowly but surely putting downlighters in, new watert feeds, etc etc, so I just wanted a quick and cheap way to stop us losing what heat we do have to the air! Likewise I didn't fancy cutting out all the kingspan, only for pipes and ducts and so on to move as the plumb/leccy is redone, and then have to do it all over again.
Am hoping 148 rolls will be enough.
Come what may, nothing will be nastier than the weekend taking the old stuff out.... god that was horrid. Height of summer, and trying to guess what the darkened piles were before you put a hand in: knackered glass fibre, rat poo, dead rat, other rodent, nest, god knows what..... yuck!
Kingspan is the final plan, but right now we are part way through ripping out all the plumbing and leccy, and slowly but surely putting downlighters in, new watert feeds, etc etc, so I just wanted a quick and cheap way to stop us losing what heat we do have to the air! Likewise I didn't fancy cutting out all the kingspan, only for pipes and ducts and so on to move as the plumb/leccy is redone, and then have to do it all over again.
Am hoping 148 rolls will be enough.
Come what may, nothing will be nastier than the weekend taking the old stuff out.... god that was horrid. Height of summer, and trying to guess what the darkened piles were before you put a hand in: knackered glass fibre, rat poo, dead rat, other rodent, nest, god knows what..... yuck!cjs said:
You can probably crush the 150 stuff down under any floor boards, that's what I did.
Do not do this! The main reason for the insulation working is that it slows air movement through it down. Ifyou crush the insulation you are effectively nullifying it's effectiveness.
I would just go in to B&Q and pick up some cheap stuff, which is the right depth. Fill up the joist depth and then
crosslay with the better stuff that you have.
Edition, as a sensible poster said above, just crush it down with the weight of the chipboard flooring sheets, it won't result in the end of the world!
Alternatively you could spend hours running some 3x2" timbers along the nodal points of the trusses, then span that with more 3x2's running the same way as the trusses, then board on top of that. You will have wasted much time and money, and if anyone could say they noticed a difference in living space temperatures due to less heat loss they would be a liar, or a do gooder.
Alternatively you could spend hours running some 3x2" timbers along the nodal points of the trusses, then span that with more 3x2's running the same way as the trusses, then board on top of that. You will have wasted much time and money, and if anyone could say they noticed a difference in living space temperatures due to less heat loss they would be a liar, or a do gooder.
People usually only want to board the middle half or third of the area anyway so start off by boarding that and then lay the extra insulation on the outer quarters/thirds.
For the OP now I have a little better understanding of what you are trying to do I'd say make yourself some access boards, say 12' long o/o t&g held together with 2"x1" and 15" wide. Paint the ends of these boards for the length of the joist spacing (450/600) and don't stand on the painted area. You can then put these boards down where ever you want to walk. Then attach all of the services near the bottom of the rafters above insulation level. I hope that you've got a very good mask because you're going to be up there for quite a while.
For the OP now I have a little better understanding of what you are trying to do I'd say make yourself some access boards, say 12' long o/o t&g held together with 2"x1" and 15" wide. Paint the ends of these boards for the length of the joist spacing (450/600) and don't stand on the painted area. You can then put these boards down where ever you want to walk. Then attach all of the services near the bottom of the rafters above insulation level. I hope that you've got a very good mask because you're going to be up there for quite a while.
eps said:
deeps said:
Edition, as a sensible poster said above, just crush it down with the weight of the chipboard flooring sheets, it won't result in the end of the world!
Just to reiterate this is not a sensible route.Air is a very good insulator - but only when it can't move. The whole point of the quilt is to be fibrous and trap air (same with down jackets or duvets). If you crush the material then you reduce the overall insulation to just the thermal resistivity of the quilt - which will be a lot lower than millions of air pockets.
I love the way these things are never straight answers! Good ole PH.
Well, I got a heck of a lot done yesterday afternoon, the space blankety stuff is very very easy to put down and so nice not to be handling bare fibres. I've also found it's "firm" enough when expanded to support its own weight, so cross laying has been a cinch and didn't require batten on the joists, except around the downlighters.
As for the walkways, yes they're currently T&G boards, so I will just build a small frame raised up by about 6" and then re-lay the same boards over it, and likewise for the sections I want to board out and use as storage I'll do much the same - a couple of uprights off the joists, some braces, and then boards over the top.
Oh, and for the chap who said about the mask and unpleasantness - this is EASY. Yes I have the gimp suit and mask, but laying this is muchly preferable to the summer's job which was taking out all of the old 50s glassfibre... now that WAS unpleasant!
Well, I got a heck of a lot done yesterday afternoon, the space blankety stuff is very very easy to put down and so nice not to be handling bare fibres. I've also found it's "firm" enough when expanded to support its own weight, so cross laying has been a cinch and didn't require batten on the joists, except around the downlighters.
As for the walkways, yes they're currently T&G boards, so I will just build a small frame raised up by about 6" and then re-lay the same boards over it, and likewise for the sections I want to board out and use as storage I'll do much the same - a couple of uprights off the joists, some braces, and then boards over the top.
Oh, and for the chap who said about the mask and unpleasantness - this is EASY. Yes I have the gimp suit and mask, but laying this is muchly preferable to the summer's job which was taking out all of the old 50s glassfibre... now that WAS unpleasant!
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