| Loft roof-boards.... advice please 17:17 - Nov 21 with 3607 views | Juzzie |
No, not QPR related but just after some advice please.
Using this photo from the internet as reference, my loft has insulation wadding in-between the roof struts you can see at the top of the picture.
Thing is, over time a few of the waddings partially or mostly come loose then hang down and I keep having to shove them back into place.
So, my plan is to put boarding up not only to hold the insulation wadding in place but also make the loft look a bit neater.
I can't see any boards needing to be thick as the wadding is not that heavy, just enough to hold it in place with screws so anything around 3mm will probably suffice I'd guess.
However, my dilemma is choice of material. I was thinking of MDF but not sure as apparently gives of gasses over time. The loft is well ventilated and access to it is via a hatch (with draught seals) so I would imagine any gasses would just vent out of the house rather than down into the house.
So, is MDF OK or a no-no and something else recommend?
Thanks in advance.
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| Loft roof-boards.... advice please on 17:31 - Nov 21 with 3562 views | GloryHunter |
Sounds as though you have mineral wool insulation between the rafters (not "struts"). The cheapest board material would be OSB - "Oriented Strand Board" - sold as Sterlingboard or other brand names. Before you screw the boards to the rafters, you are supposed to staple a polythene vapour barrier across the rafters - ie on the "warm" side of the insulation, to stop warm, moist air from the house passing through and condensing out on the "cold" side of the insulation, where it might rot the rafters and tile battens. |  | | |
| Loft roof-boards.... advice please on 17:35 - Nov 21 with 3549 views | Juzzie |
| Loft roof-boards.... advice please on 17:31 - Nov 21 by GloryHunter |
Sounds as though you have mineral wool insulation between the rafters (not "struts"). The cheapest board material would be OSB - "Oriented Strand Board" - sold as Sterlingboard or other brand names. Before you screw the boards to the rafters, you are supposed to staple a polythene vapour barrier across the rafters - ie on the "warm" side of the insulation, to stop warm, moist air from the house passing through and condensing out on the "cold" side of the insulation, where it might rot the rafters and tile battens. |
Thanks GH (and yes, rafters, lol!).
I have some of the insulation in the garage so I'll check what material it is but that sounds about right. | | | |
| Loft roof-boards.... advice please on 17:36 - Nov 21 with 3533 views | Sharpy36 |
You could use plasterboard.
It will need scoring obviously before you try getting it through the hatch. Be good for decorating should you want to use your loft for extra space. Cheaper than any wood based material also. |  |
| 'You didn't know that was wrong, but now you do. If you do it again, I'll know you are doing it on purpose.' |
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| Loft roof-boards.... advice please on 17:45 - Nov 21 with 3499 views | GloryHunter |
| Loft roof-boards.... advice please on 17:36 - Nov 21 by Sharpy36 |
You could use plasterboard.
It will need scoring obviously before you try getting it through the hatch. Be good for decorating should you want to use your loft for extra space. Cheaper than any wood based material also. |
The risk with plasterboard in an unheated roof space is that it can absorb moisture from the atmosphere and then sag. | | | |
| Loft roof-boards.... advice please on 17:53 - Nov 21 with 3475 views | Sharpy36 |
Moisture board ?
But then it starts getting expensive. | |
| 'You didn't know that was wrong, but now you do. If you do it again, I'll know you are doing it on purpose.' |
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| Loft roof-boards.... advice please on 18:45 - Nov 21 with 3400 views | ted_hendrix |
Don't use a hammer and nails when fixing the boards or you run the risk of dislodging your roof tiles, use screws (It's easier and more exact).
When I done mine years ago as a back up I went on me roof and fixed a couple of venting ridge tiles, you might already have them installed?
Do a cutting list to work out the waste from off cuts to save yourself money, from the picture It looks like 400mm centres.
Dont cut anything in the roof space if at all possible, do your measures and cut everything outside and hump It upstairs.
Some builders merchants will cut the boards to size for you for a fee but It will save you a lot of time and effort In the long run.
You'll have an aching back by the time you've finished. |  |
| My Father had a profound influence on me, he was a lunatic. |
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| Loft roof-boards.... advice please on 19:44 - Nov 21 with 3343 views | kensalriser |
Before you start check your insulation is current spec and maxed out, you won't want to be redoing it later! |  |
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| Loft roof-boards.... advice please on 01:22 - Nov 22 with 3117 views | PunteR |
You shouldn't have rockwool insulation between your rafters.
Do you have insulation on the floor of your loft?
Your suppose to have about 250mm of rock wool insulation laid across the ceiling joists on the floor of your loft.
This makes it difficult to lay a solid floor to walk on. If you're insulating the roof area you need a hardboard insulation, Kingspan, Celetex . I'm not 100% sure on current regs off the top of my head or the thermal calculations but you need at least 100mm thick board in-between rafters with a 50mm air gap between the back of the insulation and the roof tiles. (You really need breathable roofing felt on the outside. )
This means the rafter timbers need to be at least 150mm depth or 6 inches in old money.
Plasterboard would be your best option. You can get plasterboard with added insulation of up to 50mm stuck to the back of the board which you can screw to the rafters. This gives you extra insulation obviously plus prevents cold bridging through the timber rafters.. Don't use MDF or OSB. You won't get any sagging if the space between rafters are 400mm centers. Use 12.5mm thick plasterboard. Foiled back board is good but you also have the option of moisture board(green) acoustic (blue) fire rated(pink)
If you decide to use plasterboard and you're going to struggle getting the board through you loft hatch get a Stanley knife and a straight edge and score the back of the board. You can then snap and fold the board in half but it stays intact because of the paper. 1200mm folds to 600mm and you should be able to pass that through the hatch.
Hope that helps a bit and I explained that ok. [Post edited 22 Nov 2022 1:30]
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| Loft roof-boards.... advice please on 01:42 - Nov 22 with 3102 views | PunteR |
| Loft roof-boards.... advice please on 01:22 - Nov 22 by PunteR |
You shouldn't have rockwool insulation between your rafters.
Do you have insulation on the floor of your loft?
Your suppose to have about 250mm of rock wool insulation laid across the ceiling joists on the floor of your loft.
This makes it difficult to lay a solid floor to walk on. If you're insulating the roof area you need a hardboard insulation, Kingspan, Celetex . I'm not 100% sure on current regs off the top of my head or the thermal calculations but you need at least 100mm thick board in-between rafters with a 50mm air gap between the back of the insulation and the roof tiles. (You really need breathable roofing felt on the outside. )
This means the rafter timbers need to be at least 150mm depth or 6 inches in old money.
Plasterboard would be your best option. You can get plasterboard with added insulation of up to 50mm stuck to the back of the board which you can screw to the rafters. This gives you extra insulation obviously plus prevents cold bridging through the timber rafters.. Don't use MDF or OSB. You won't get any sagging if the space between rafters are 400mm centers. Use 12.5mm thick plasterboard. Foiled back board is good but you also have the option of moisture board(green) acoustic (blue) fire rated(pink)
If you decide to use plasterboard and you're going to struggle getting the board through you loft hatch get a Stanley knife and a straight edge and score the back of the board. You can then snap and fold the board in half but it stays intact because of the paper. 1200mm folds to 600mm and you should be able to pass that through the hatch.
Hope that helps a bit and I explained that ok. [Post edited 22 Nov 2022 1:30]
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Just to add, you will need either a vented soffit to allow the airflow behind your insulation. If not you will have to retro fit vents to your soffit. Every 400mm .
Give us a shout if you're not sure. [Post edited 22 Nov 2022 1:45]
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| Loft roof-boards.... advice please on 11:29 - Nov 23 with 2777 views | Juzzie |
Thanks everyone! I was originally going to just screw in some thin MDF boards but I'm aware there are all sort of regulations, choices of board etc hence putting the question up here.
The above picture was just something I got off the internet, I've managed now to get some pictures of the loft itself plus what's in the shed.
The floor was boarded up but I don't think any insulation was put underneath, i'll have to pop up there and have another check.
The insulation rolls were put in-between the rafters. As you can see, some of them have come loose hence the need to put something up to hold them in place.
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| Loft roof-boards.... advice please on 13:38 - Nov 23 with 2658 views | PunteR |
| Loft roof-boards.... advice please on 11:29 - Nov 23 by Juzzie |
Thanks everyone! I was originally going to just screw in some thin MDF boards but I'm aware there are all sort of regulations, choices of board etc hence putting the question up here.
The above picture was just something I got off the internet, I've managed now to get some pictures of the loft itself plus what's in the shed.
The floor was boarded up but I don't think any insulation was put underneath, i'll have to pop up there and have another check.
The insulation rolls were put in-between the rafters. As you can see, some of them have come loose hence the need to put something up to hold them in place.
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That insulation isnt adequate mate but if you are just looking to keep the stuff from falling out Sharpys link looks good to me. | |
| Occasional providers of half decent House music. |
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| Loft roof-boards.... advice please on 15:06 - Nov 23 with 2570 views | Boston |
If it's just a question of holding up batts - we just zig zag wire from rafter to rafter, clipping in place with staples, though roofing nails will do. Relatively inexpensive, easy enough for one person. |  |
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| Loft roof-boards.... advice please on 15:24 - Nov 23 with 2541 views | Juzzie |
| Loft roof-boards.... advice please on 15:06 - Nov 23 by Boston |
If it's just a question of holding up batts - we just zig zag wire from rafter to rafter, clipping in place with staples, though roofing nails will do. Relatively inexpensive, easy enough for one person. |
My main aim is just to keep that wadding in place. The idea of using thin boards was secondary in order to just tidy it up and look nicer. | | | |
| Loft roof-boards.... advice please on 15:44 - Nov 23 with 2517 views | PunteR |
| Loft roof-boards.... advice please on 15:24 - Nov 23 by Juzzie |
My main aim is just to keep that wadding in place. The idea of using thin boards was secondary in order to just tidy it up and look nicer. |
Use 3mm ply then. Mdf not very good in damp conditions which you will get with your method. Ply a bit more resilient but just doesn't have a smooth surface . | |
| Occasional providers of half decent House music. |
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| Loft roof-boards.... advice please on 21:44 - Nov 23 with 2389 views | Boston |
| Loft roof-boards.... advice please on 15:44 - Nov 23 by PunteR |
Use 3mm ply then. Mdf not very good in damp conditions which you will get with your method. Ply a bit more resilient but just doesn't have a smooth surface . |
Is MDO board available in the UK?
Any type of plaster board work in an attic is strenuous and not one I'd recommend unless you're physically fit and bloody minded.
Most products, wood or whatever, come in sheets which will probably have to be cut / ripped into 24" lengths(pardon my English). But at least the wood doesn't get beaten up as you push it up through the attic door. | |
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| Loft roof-boards.... advice please on 22:10 - Nov 23 with 2370 views | ted_hendrix |
| Loft roof-boards.... advice please on 11:29 - Nov 23 by Juzzie |
Thanks everyone! I was originally going to just screw in some thin MDF boards but I'm aware there are all sort of regulations, choices of board etc hence putting the question up here.
The above picture was just something I got off the internet, I've managed now to get some pictures of the loft itself plus what's in the shed.
The floor was boarded up but I don't think any insulation was put underneath, i'll have to pop up there and have another check.
The insulation rolls were put in-between the rafters. As you can see, some of them have come loose hence the need to put something up to hold them in place.
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Looking at them pictures I'd safely say that-that old insulation in your loft contains carcinogenic materials which Is very dangerous!!!
Up to you of course but you definately need to wear a mask and gloves and goggles as a minimum before touching that stuff or going near It again.
Not going OTT but be bloody careful from now on you do not want the dust from that stuff entering your house. | |
| My Father had a profound influence on me, he was a lunatic. |
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| Loft roof-boards.... advice please on 22:15 - Nov 23 with 2360 views | Juzzie |
| Loft roof-boards.... advice please on 22:10 - Nov 23 by ted_hendrix |
Looking at them pictures I'd safely say that-that old insulation in your loft contains carcinogenic materials which Is very dangerous!!!
Up to you of course but you definately need to wear a mask and gloves and goggles as a minimum before touching that stuff or going near It again.
Not going OTT but be bloody careful from now on you do not want the dust from that stuff entering your house. |
Cheers Ted.
It was installed last year so i hope it’s up to date regulation-wise! The rolls in my shed is what was left over from what they bought (from Wickes I think) | | | |
| Loft roof-boards.... advice please on 22:27 - Nov 23 with 2345 views | Boston |
| Loft roof-boards.... advice please on 22:15 - Nov 23 by Juzzie |
Cheers Ted.
It was installed last year so i hope it’s up to date regulation-wise! The rolls in my shed is what was left over from what they bought (from Wickes I think) |
That product is usually used in masonry insulation.
Edit, I'm slipping, they're batts not rigid! [Post edited 23 Nov 2022 22:31]
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| Loft roof-boards.... advice please on 00:16 - Nov 24 with 2297 views | PunteR |
| Loft roof-boards.... advice please on 21:44 - Nov 23 by Boston |
Is MDO board available in the UK?
Any type of plaster board work in an attic is strenuous and not one I'd recommend unless you're physically fit and bloody minded.
Most products, wood or whatever, come in sheets which will probably have to be cut / ripped into 24" lengths(pardon my English). But at least the wood doesn't get beaten up as you push it up through the attic door. |
MDO is not something I've used. Had a quick look online and it is available in the UK. As with a lot of sheet material it's expensive. It's basically just ply with a mdf veneer finish to one side by the look of it.
I'll say it again but i really wouldnt recomend Juzzie's method of insulating his house. Unless there's adequate insulation under the floor boards then 100mm of rockwool shoved between rafters is not the way to do it. Covering it all up is going to add to further problems down the line. Your basically trapping the moisture behind the board. | |
| Occasional providers of half decent House music. |
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| Loft roof-boards.... advice please on 09:18 - Nov 24 with 2218 views | Juzzie |
| Loft roof-boards.... advice please on 00:16 - Nov 24 by PunteR |
MDO is not something I've used. Had a quick look online and it is available in the UK. As with a lot of sheet material it's expensive. It's basically just ply with a mdf veneer finish to one side by the look of it.
I'll say it again but i really wouldnt recomend Juzzie's method of insulating his house. Unless there's adequate insulation under the floor boards then 100mm of rockwool shoved between rafters is not the way to do it. Covering it all up is going to add to further problems down the line. Your basically trapping the moisture behind the board. |
The loft is well ventilated, you can feel the draught while up there, so I think I'll just put some of that galvanized steel banding across the rafters to hold the wadding in place. | | | |
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