insulating shed and cheapest way to clad inside

[mickthetree]

Hey all

I'm putting in SWA cable today and a small garage consumer unit and will need to clad over the top of some of the battens to mount it, so thought i'd look at boarding it out fully and putting in some insulation at the same time.

I see that b&q are doing buy one get one free on loft insulation. Would this be a suitable product to use in my shed as insulation between the battens with cladding over?

Also what is the cheapest way to clad the inside of a shed? 12mm OSB?

 

[OPJ]

Yep, I think 11mm OSB is the cheapest way to clad the inside. Plasterboard is also fairly cheap but, it 'falls apart' if you get it wet and won't stand up to any kind of abuse. :wink:

 

[Boz62]

Yep, I used 11mm OSB as the cheapest interior cladding route. If you paint it, it's harder work due to its' roughness, however. I used rockwool batts for wall insulation - the sort usually fitted in brick cavities. They are thinner, for a given insulation level, so take less valuable space and are better sound insulators.

This is my first winter with a usable workshop after all that - well worth it

Boz

 

[BigShot]

Loft insulation (I assume you mean the thick fibreglass type insulation) relies on the air trapped between the fibres for insulation so if you were planning on compressing it into a smaller space than it naturally takes up you'll reduce its effectiveness.

Keep that in mind when you're planning what to do.

Other solutions are polyurethane boards (kingspan, celotex and the likes), polystyrene boards (jablite) and foil membranes (web dynamics thinsulex, tri-iso and so on).

The foil and board methods aren't the cheapest, but since neither will need compressing to fit into your walls (the foil is about 15mm thick when uncompressed and the poly boards come in thicknesses down to about 15mm which would allow you to find a balance between insulation and space inside the shed) they should provide more effective insulation.

You may need to consider things like vapour barriers and ventilation for the walls. I'm afraid I can't offer as much input on that as I just work to a couple of standard designs (cold roof and warm roof) when designing loft conversions but you should have a look into it and see what's what.

 

[DeepBlue]

I would have loved to use celotex to insulate my shed, but as it's only a hobby workshop I made do with el-cheapo loft insulation and I couldn't be more please with the result.

After I insulated it, I cladded everything with B&Q finest 12mm chipboard which was the cheapest stuff I could find (excluding plasterboard). I remember doing the cladding in the depths of winter, in a tee shirt, with the temperature outside in negative figures and needing to open a window because it was too hot inside, so I guess it must do the trick!

 

[BigShot]

I remember doing the cladding in the depths of winter, in a tee shirt, with the temperature outside in negative figures and needing to open a window because it was too hot inside, so I guess it must do the trick!

Forget U-values, E-values and anything else that's designed to confuse people new to insulation - that is, without question, the best indicator of the effect insulation has on warmth.

The ventillation aspect should still be thought of - wouldn't want mold or rot developing in the walls - but as far as warmth that's absolutely all you need to know.


Was your "el-cheapo" loft insulation the fibreglass rolls or a board one? How thick were they and what size a space did you put them into?

 

[DeepBlue]

I think it was this stuff:

http://www.diy.com/diy/jsp/bq/nav.j...refview=search&ts=1259144277655&isSearch=true

100mm fibreglass rolls in 400mm x 75mm spaces. Yes I did squish it in in places, and yes I'm sure it did compromise my U-value, but as far as I'm concerned it didn't make any difference

 

[BigShot]

As expected.
Yea, squashing it will certainly have affected the U-value, but quite right - what does it matter?
If you can work in there in a t-shirt in sub-zero outside temperatures - it works... U-values don't come into it!

Kinda makes it clear just how mad the insulation regulations for houses are. Foil membranes, for example, are cheaper and easier to fit than anything that meets the official requirements - but they do a perfectly good job. Once things are "warm enough" in the dead of winter - anything else is just overkill!

 

[LocalOak]

I used some cheap kingspan offcuts from Seconds and Co and clad with OSB. To reduce the weight on doors and cieiing I used 6mm ply. Its all pretty rough and ready, just cut the kinspan roughly to shape and wedged it between the battens not worrying too much about tight fit and drafts. I can now work happily in the shop whatever the weather.

Toby

 

[disco_monkey79]

What sort of impact will the rolls of loft-type isulation, or the polystyrene sheets make in terms of sound insulation?

If the answer is "not much", what's the best for both sound AND heat insulation?

 

[DeepBlue]

I think the best answer I can give is "better than nothing". As a very subjective assessment, lots of sound escapes from around the windows and doors, which I need to steal.

I did look in to making it properly sound proof (so I could use my planer thicknesser at 3.00am if it took my fancy ) 8), and it was prohibitively expensive. As I understand it the "proper" way is to build a room within a room with special fixings which damp the vibrations to hold a second skin away from the outside walls. Then you have to clad everything with expensive sound absorbent material, buy special double or triple glazed windows, etc.

You can still hear me making a noise, but I have very tolerant neighbours, and to be fair the noise with everything closed up is no worse than someone mowing the lawn or hoovering. I just stick to working in reasonable hours

 

[BigShot]

The more dense your insulation is, the better it will insulate against sound.

Stud walls in houses usually have 50mm of 10kg/m³ Rockwool - but that's not so much for keeping in the sound of a screaming router (bear in mind that it also has plasterboard and a plaster skim on both sides of the wall too) - maybe that'll help as a starting point though.

 

[studders]

lots of sound escapes from around the windows and doors, which I need to steal.

:shock:

 

[studders]

Build Center still have an offer on for 100mm loft insulation @ £4.49 a roll. Search for DIY100.

hth

 

[DeepBlue]

lots of sound escapes from around the windows and doors, which I need to steal.

:shock:

Doh! Obviously that should have been "seal".

Although, thinking about it if I were to just nick some nice soundproof doors and windows then problem solved!

 

[mickthetree]

blimey, obviously everyone likes to keep warm!

Thanks for all your suggestions. I only have a small 8 x 10 shed but its getting colder so thought I'd look into it.

Cheers studders!! thats a much better price than I had seen elsewhere!!

 

[MikeG.]

Kinda makes it clear just how mad the insulation regulations for houses are. Foil membranes, for example, are cheaper and easier to fit than anything that meets the official requirements - but they do a perfectly good job. Once things are "warm enough" in the dead of winter - anything else is just overkill!

No no no!!!!!!!

Granted there is a law of diminishing returns at play with insulation depth (ie the first inch of insulation when you have none at all does an awful lot more for the thermal efficiency of a building than, say an extra inch when you already have 12), but more and more insulation means less and less fuel. End of story.

As per other threads, it is perfectly possible to have houses in the UK which require no heat in the winter, whatsoever, to maintain temperatures at around 20C indoors, but they require levels of insulation (as well as other design features) which are well over the levels you describe as "mad". Please see "my heating has just come on".

Finally, those "thinsulations" you refer to are not as effective as you think. Firstly, they require a 25mm air gap each side of them, so despite their 15mm thickness, they actually take up the same room (65mm min.) that could be fully filled with Kingspan, for instance, which would achieve much higher levels of thermal benefit. Secondly, they are having difficulty proving that they work. Thirdly, in rooves they require additional insulation to reach the min. requirements of Part L of the regs.

Mike

 

[OldWood]

Can I throw in a wobble ball here please - and it may well be that good building principles do not apply to workshops.

One the things to bear in mind with insulation is that (A) it reduces air flow (intentionally of course to act as an insulant, but bear with me) and (B) it has a temperature gradient across it.

Now if you reduce air flow you reduce the ability of the structure to get rid of moisture, and most workshops have thin external walls which may well not be 100% watertight, so you are now jamming in a material against the outer skin which potentially is not going to allow that moisture to dissipate.

The temperature gradient across the insulation is the next problem as the dew point is quite likely to occur within the insulation in winter conditions, which adds more moisture to that possibly seeping through the external cladding.

Good practice therefore says that there should be a breathing air gap between the insulation and the outer cladding, and that there should be a membrane on the inside of the insulation to prevent warm moist air getting into it from the workshop.

That can be done perfectly effectively and cheaply in a 3" cavity but does require more work.

OW

 

[MikeG.]

Now, where is that "Mike's guide to shed building" that I keep banging on about?!!!

You are dead right, and that is why I keep on advocating a gap behind the outer cladding. That and a masonry plinth are the difference between a temporary shed and a proper workshop. You may have seen that I always advocate using a sheathing board on the inside of the wall. OSB and ply have a high enough resistance to the passage of vapour that they work perfectly acceptably as a vapour barrier, as well as making a good robust lining for a workshop.

The insulation isn't the problem........it is the detailing, as always.

Mike

 

[OldWood]

Mike - I'm interested that you reckon the OSB and ply are adequate moisture barriers - would have save me putting in a membrane. How do they differ from plaster board with paint on it ? Or is that the household situation is so much warmer and potentially damper that a membrane is necessary there?

OW