Insulating a metal shed

[Mudmonkey]

The time has come that I need to move the Land Rover/car bits out of the spare bedroom and into the garden, we've only been in the new house for 6 months! The previous tenant had a dog kennel and had poured a generous sized (10x10ft) concrete base in the garden. Due to ease of transport when we eventually move on to another rental (or actually buy a house, god forbid) and also the significant cost saving over their wooden counterparts, I've been looking at metal sheds such as this.

I know I'm going to need to insulate this to stop condensation so a couple of questions for you all before I commit;

I'm assuming there is no damp proof membrane in the concrete slab, the concrete also smells very "doggy" when it gets a bit warm. I was planning to lay a membrane and some osb and then build the shed on top of that to stop moisture/stench from penetrating from underneath. Does this seem sensible? Anyone got any different ideas?

What should I use to insulate the walls/roof without eating into my storage and work space? I had an idea of using 5mm foil backed foam underlay that they use for laminate flooring like this. I'm hoping the foil would give some minor spark protection for the foam so that it doesn't disappear as soon as I start up the grinder. 

Any other suggestions will be gratefully received. 

 

Edited November 4, 2017 by Mudmonkey

[crclifford]

I wouldn’t fit foil backed foam underlay, to the walls and roof. I would say 25mm kingspan or as thick as you can get between the uprights.  If you wanted something more flexible, then the foil covered bubble wrap insulation is good. I mean the stuff that gets added to roof spaces, like this https://www.tradestoreonline.co.uk/Vapour-Barrier-and-Thermal-Insulation-Aluminium-Foil-Membrane?gclid=EAIaIQobChMIpv21sv2m1wIViz8bCh1-Qg6oEAQYBSABEgL86_D_BwE 

[Retroanaconda]

A couple of things spring to mind regarding your slab:

1. If the shed does not reach the edges of the slab you will need to think about sealing the bottom so water doesn’t come in under the walls. Custom-building to suit the slab solves this, but doesn’t help with your desire to move it.
2. Assuming there is no DPM under the slab as you say, is it sitting proud of the ground? If it is and you can clear the soil back from it slightly at the edges to stop groundwater sitting against it then you will have a much lower level of moisture coming up through it. If the slab is sitting down into the ground, or at a low point, it will be much more of a struggle.

Regarding insulation, I would think Kingspan or polystyrene type sheets are going to be your best bet. You need to stop the internal air from reaching the metal skin around the entirety of the walls and ceiling. You’ll also need an air gap between that skin and the sheets, although being metal you’ll not need the amount of airflow that one would in order to prevent rot in a wooden structure.

The slab would be my first concern, even with good insulation if you’ve got large amounts of moisture coming up through it all winter you'll struggle big time. My workshop is built on a kennel slab also, and it doesn’t have a DPM. I have suffered with a small amount of damp coming through the floor however since I dug a drain round the slab things have been largely fine. Guttering is essential.

I was informed when I built mine that kennel slabs soak up dog urine over the years which can give you your funky smell as well as rotting metal things due to the urea content. Happily mine never had any smells and has been fine, so I can only assume they were well trained dogs or the kennels had good flooring.

When I started to build mine I also had grand intentions of making it portable, in reality though this just isn’t practical and I will have to leave it when I move. Mine is built out of wood though.

[Mudmonkey]

Thanks for the suggestions so far, the shed arrives tomorrow in Meccano form.

On 11/5/2017 at 11:14 AM, Retroanaconda said:

The slab would be my first concern, even with good insulation if you’ve got large amounts of moisture coming up through it all winter you'll struggle big time. My workshop is built on a kennel slab also, and it doesn’t have a DPM. I have suffered with a small amount of damp coming through the floor however since I dug a drain round the slab things have been largely fine. Guttering is essential.

I was informed when I built mine that kennel slabs soak up dog urine over the years which can give you your funky smell as well as rotting metal things due to the urea content. Happily mine never had any smells and has been fine, so I can only assume they were well trained dogs or the kennels had good flooring.

The slab is proud of the ground by a small amount, it is also surrounded on two sides by gravel, the other two sides are stone wall so I don't think moisture coming up through the floor will be a huge issue. The plan for the floor is 1 sheet of DPM laid on top of the concrete and then T&G OSB boards to the size of the shed base. I was going to fold the DPM over the boards and staple to the top side, trim off any excess and then bolt the shed through the boards to the concrete.

The slab looks quite new so can't have had much of an exposure to the dogs before we moved in. I had noticed during the summer that there was a noticeable smell on a hot day, hopefully the above should stop it penetrating inside anyway.

On 11/5/2017 at 8:09 AM, crclifford said:

If you wanted something more flexible, then the foil covered bubble wrap insulation is good. I mean the stuff that gets added to roof spaces, like this https://www.tradestoreonline.co.uk/Vapour-Barrier-and-Thermal-Insulation-Aluminium-Foil-Membrane?gclid=EAIaIQobChMIpv21sv2m1wIViz8bCh1-Qg6oEAQYBSABEgL86_D_BwE 

Yes, didn't think of the bubble wrap roofing stuff. I think I'll go with that. By no means do I expect it to be tropically warm in there, I just want to prevent condensation on things mainly.

[Cynic-al]

I used polystyrene sheet covered with OSB but that's because it's what I could get free.

The tin sheds seem to be quite easy to break into. Have you looked at the cost of getting the inside spray polyurethane type foamed like they do with farm buildings, boats etc? It covers everything and might stick the panels together a bit to help with security?

Why not paint clean the slab and paint it with a 2 part resin floor paint before you put the shed on. It'll gunge up all the holes and should help keep the smell away. I used firwood with their acid etch and degreaser but it depends what you want to spend and what type of contrete floor it is.

 

[Mudmonkey]

1 hour ago, Cynic-al said:

Why not paint clean the slab and paint it with a 2 part resin floor paint before you put the shed on. It'll gunge up all the holes and should help keep the smell away. I used firwood with their acid etch and degreaser but it depends what you want to spend and what type of contrete floor it is.

Would an epoxy resin paint prevent damp coming up through the slab? This would be a better option for me if so.

 

[Cynic-al]

You can buy damp seal paint to prevent damp on floors and walls but I must confess I don't know much about it. I believe it's bitumen based like the roof sealer. I don't know how abrasion resistant it would be but if your putting another floor on top of it? It claims it is vapour resistant so it should stop the smell coming through although they might still go around?

Like this;

https://www.permagard.co.uk/damp-proof-paint?gclid=Cj0KCQiArYDQBRDoARIsAMR8s_TaSvgAroL6De5Kfwkf01vq-Au_xomcNfYTTyGZuXOorWeQwdgDZz0aAkP-EALw_wcB

Edited November 6, 2017 by Cynic-al

[Paddy]

Goole search for an appropriate sealer, get the wrong one and it will blister up or lift off.

You mentioned grinding so make sure insulatio is fire proof, look at kingspan foil backed or equivalent.

I’d use a dpm, with roofing 2x1 treated battens, with the floor ontop.

Consider a kicker plate around the outside walls of the shed to throw rain water away from the wall/floor joint.

Get an estimate from a builder and pick his brains.....

[JohnnoK]

If you want to stop the doggy smell, get yourself a few liters of Surgical Spirit and liberally apply to the slab.

We had an issue with a cat peeing on my daughter's bedroom floor and a good dose of the Spirit did the job for that.

[Tracy]

Hi I have a 10×12 steel shed, only a couple of years old. It's in great condition, and I have 5 kids. I'm just wondering could I insulate it to make it into a toy/playroom for my children?? Our home is very small and I really could do with a toy room, and somewhere for the older girls to hang out with friends, especially during Winter time... 

Can someone professional give me any advice if this can be used for what I need it for?? Also best/cost saving way to do it, if I can. 

Would really appreciate the help

Thank you 

[Gazzar]

Hi Tracey, 

 

I suggest you ask on the www.boards.ie forums. They're a section for domestic DIY projects and would know what the local Irish suppliers would have in stock, and the local regulations.

This forum is more geared towards Landrovers and associated projects, so, while no doubt you'd get advice, it might be biased toward Landrover workshops!