Jump to content

Insulating a wooden shed / workshop


Recommended Posts

Exciting times - shed shopping at last! ^_^

We're about to get a wooden shed (10x12ft) which will act as a workshop/lab for various tinkering and inventing - mostly electronics and finer things like that rather than big hammers & welding, as that stuff lives in the garage.

What with the grim northern winters oop Basingstoke, we need to insulate it somehow - the basic principle is the blindingly obvious "insulate between the struts & board over the top", plus a layer of something over the floor and then a bit more board (and possibly some cheap lino or similar).

But, what is the most suitable sort of insulation for the job?

I don't really want to use rockwool as it's a pain, I've heard the more rigid foil-backed panels such as "celotex" are better insulators and are easier to cut to size & slot in.

Floor-wise I've no idea - B&Q have some jigsaw-style stuff designed to go under a laminate floor which is about 10mm thick and foil-backed. The floor will have a couple of workbenches and probably a heavy shelving unit stood on it, so it wants to be reasonably solid!

Also planning to double-glaze by nailing a perspex panel on the inside of the window frame, creating an air-gap.

Will be running round with the foam sealing strip / silicone sealant to keep the draughts out too.

Any thoughts, suggestions, etc. welcomed!

Link to comment
Share on other sites

Not sure what it is (I can ask) but I used a firesafe foam, comes in all sorts of thicknesses and has a silver foil coating each side,

I shoved that up, then boarded on top with 1/4 inch Ply screwed to the beams where marked,

Made a HUGE difference, used a saw table, stanley knifes and simple saw and cordless and 1,000,000 screws !

Much nicer than rockwool / beans etc

Nige

Link to comment
Share on other sites

Celotex is a bit spendy, but really, really easy to use, and works a treat. Get some silver aluminiumised tape to seal gaps/joins etc. Maybe have a chat with a builder friend or something, as they can generally save you a packet on the celotex.

There's also a foil/bubblewrap combo stuff that's effective while being only about 6mm thick for tighter areas, eblag is the place to find it.

Get a cheap mastic stuff to seal up gaps in the structure before you start fitting the insulation.

If you can put an insulation on the bottom of the floor between the joists before you turn it over it'll help a lot, and be better than the thin stuff you mentioned, and give you a firmer floor.

Also, a curtain over the door, and insulating the door will help a lot. Shed doors aren't really designed to seal very well...

Hope that helps.

Link to comment
Share on other sites

What I like to do first is to staple some black damp-proof membrane underneath the floor cross bearers, and fold it upwards and staple to their sides, forming a good waterproof membrane between the shed and the concrete pad or slabs.( Sheds rot from the bottom up usually).

To form a complete moisture barrier I also staple strong plastic sheeting (shrink wrap type is perfect) to the wooden inside walls and roof, making sure to staple back to the panels to leave a gap for your insulation.

As Mike says Celotex is easy to work with, and you will be as snug as a bug in a rug.

Then I cover everything with marine ply or hardboard nailed or screwed to the wooden battens.

I also overclad the roof with steel roof sheets.

I have used this method for my dog runs as well, but I build a wood frame and use profiled steel roof sheets for the roof and sides.

Last forever

Cheers

Barry

Link to comment
Share on other sites

Fridge, I have a mahoosive pile of polywhatsit insulation boards here, sitting outside my workshop going begging. They are tatty and have previously been used to insulate a unit on an industrial estate. Yours for free if you agree to take the whole lot so I don't have to put them on ebay / think about it any more - ideal for a workshop I reckon, and cheap enough to double the thickness if you wanted (they are 50mm)..

I also have an equally mahoosive pile of blue plasterboard, mostly 12mm, sold to me as seconds with some edge damage etc. A lot of them are in pretty good shape. Plasterboard is completely fireproof, so great for a burny / sparky workshop I think.

Same deal - if you want them for free, you can have them as long as you take the lot (use the best ones then stick the rest on ebay?)

Hold on, might have a pic...

post-139-0-05165800-1370536711_thumb.jpg

post-139-0-22949100-1370536728_thumb.jpg

post-139-0-03768300-1370536746_thumb.jpg

There is about a third of that stack of insulation again - some of which are halfs / fractions etc. I might be able to bin the really useless bits for you.

Several trailer-loads for sure, but just south of Basing St Oke towards Winch... I can forklift onto a trailer.

Let me know, cheers Al.

Link to comment
Share on other sites

I concur with the celotex. We're just building a shed at my brothers as an office and we're hoping to acquire offcuts from a builder friend. For doors and windows we've got hold of some old double glazed units from a local glass company. Might be worth asking around.

We are building it from scratch and to size using old roof timbers so it's a bit easier to make second hand windows fit

Link to comment
Share on other sites

If you are buying a shed with a wood floor you still need airflow underneath to allow the wood to dry, when the weather is wet and nasty.

I think Insulation should always be on top of the floor, and overclad with hardboard nailed down.

Lino or click floor laminate on top will go down easily on this and is pretty durable and easy to keep clean.

Cheers

Barry

Link to comment
Share on other sites

Another vote for the celotex/ kingspan- Built a workshop last year, and been able to use it through the winter with minimal heating. It also works well for deading sound.

I used this lot as a supplier:

http://stores.ebay.co.uk/secondsandco?_trksid=p2047675.l2563

Tehy sell Kingspan seconds. The definition of second is pretty good-usually things such as dinked corners or out of spec thickness, but nothing to worry about for a shed.

Link to comment
Share on other sites

As thick a layer of foam board as, space you're prepared to loose permits. Membrane under floor as Barry suggests, with more foam between membrane and floor. More in the ceiling void.

Fit a couple of fans for ventilation with flaps that close when the fan is not running. (as it will get hot in the summer) One blowing and the other sucking. Ideally put the blowing fan at floor level and the sucking one at ceiling so they are not fighting the thermal gradient. Double-glaze as you suggested which is good for security too. Also, seal the window panes in properly so it actually forms a sealed void. Might be worth sticking some Silica Gel granules in the window voids too to stop condensation.

Insulate the inside of the door with more foam to the same thickness as the walls and cover the inside with MDF (mostly for security) and seal the door surround best you can with rubber / foam.

I lined the inside of my workshop with cheap 12mm ply / block board which is strong enough to hang shelves, tools etc.

Si

Link to comment
Share on other sites

We stuck 100mm Celotex under the floor of our wooden outbuilding to insulate under the floor, and then put electric underfloor heating in to keep us warm while we work! (LR Content - strapped 3 full sheets of Celotex at a time to the roof of my Defender in January with straps through the windows/doors - and drove home slowly! There is a bit of windage up there!)

Roof insulation is two layers with a gap between of YBS Airtec double (not cheap but good. If I did it again I would probably use something better like the YBS Superquilt). We insulated between the bearers in the roof, as we wanted to see them and in winter you can see where the roof bearers run from the outside in the snow!

Windows were secondary glazed. Not as good as double glazing but better than nothing. We just put up with a bit of condensation as it is not easy to fully seal an unpainted wooden window.

I am sure it would cost less to heat if we insulated the walls, but we wanted the space and as we use it as an office, wanted the wood look!

How right SimonR is to say that it will get hot in summer. We have had 35 deg inside already this year! Might steal Simons (as always) good idea with the fans.

Martin

Link to comment
Share on other sites

Cheers guys, good info!

And Al is an absolute star :D

I'm caught in a dilemma - do I go for the moisture barrier approach and line it with plastic before insulating, but risk it being sweaty, or leave the barrier out and let everything breathe?

Link to comment
Share on other sites

FF,

I would put a membrane underneath, but if you are planning on running heating when it is cold, I wouldn't bother on the walls. That is if it isn't in an exposed location? Otherwise, I would probably look for the moisture permeable roofing felt stuff and use that so moisture inside goes out and anything outside stays outside.

HTH

Link to comment
Share on other sites

Hi Fridge

Moisture barrier is placed on the inside of the insulation.

Wind barrier is placed on theoutside of the insulation.

When placeing the moisture barrier on the inside of the insulation, then you keep the moist in the room to be dried by heat or let out by controlled ventilation.

If the moisture barrier is placed on the outside of the insulation, then the moist will be taken shape as water somewhere in the insultaion and framewotk of the shed and it will be out of your control and the framework will start to rot !

Hope this makes sence ?

Cheers

Morten, builder by trade.

Link to comment
Share on other sites

Hi Fridge

Moisture barrier is placed on the inside of the insulation.

Wind barrier is placed on theoutside of the insulation.

When placeing the moisture barrier on the inside of the insulation, then you keep the moist in the room to be dried by heat or let out by controlled ventilation.

If the moisture barrier is placed on the outside of the insulation, then the moist will be taken shape as water somewhere in the insultaion and framewotk of the shed and it will be out of your control and the framework will start to rot !

Hope this makes sence ?

Cheers

Morten, builder by trade.

Apologies- in hindsight I think Morten is right and I was wrong. That makes sense.

For the outside and roofs I have used profiled steel PVF2/ Polyester painted sheet with a " flock" coating on the inside, or with a bonded composite insulation to prevent condensation, and insulate. Probably looks a bit industrial cosmetically compared to wood.

Cheers

Barry

Link to comment
Share on other sites

Cheers guys,

The shed is 22mm tongue + groove clad so not as leaky/draughty as cheap garden storage ones.

Interior will be plaster-boarded (thanks Al!) and will have at least a frost-protection heater all year round, plus more heating when it's in use.

I'm planning to stick a vent or two in to give some airflow.

Barry - I know the stuff you mean, my other (steel) shed has the anti-drip flocking on the roof panels. The new shed is all wood though, and has to look "presentable" :glare:

Link to comment
Share on other sites

....and this http://www.bigdug.co.uk/workshop-benches-c348/garage-flooring-set-pp1358 is fantastic !

Internlocking rubber floor tiles, I put these on top of a 3/4 Plywood floor which I added on to of the "Shed Type" one, with PVA Glue and 1,000,000 screws :D

and popped this on top, makes a HUGE difference, can be trimmed mit a stanley knife !

Nige

Link to comment
Share on other sites

Cheers guys,

The shed is 22mm tongue + groove clad so not as leaky/draughty as cheap garden storage ones.

Interior will be plaster-boarded (thanks Al!) and will have at least a frost-protection heater all year round, plus more heating when it's in use.

I'm planning to stick a vent or two in to give some airflow.

Barry - I know the stuff you mean, my other (steel) shed has the anti-drip flocking on the roof panels. The new shed is all wood though, and has to look "presentable" :glare:

Fair enough buddy. My missus decided our old shed would needed to look like a beach hut so even though it was faded brown ronseal she painted it in 2 coats of cuprinol sea grass type green with cream uprights, windows, a Juniper green steel roof with goosewing grey flashings etc...

The local builders merchants told her it wouldnt work but it looks the poodles-plums.

So now I am off the hook to go fishing and shooting! Tough life!!!!

Barry

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy