Insulation & wall choice for workshop/shed in damp area

[pmr]

Hello,

Have moved into a house with a shed on the low part of the block, in heavy rain water sometimes enters because of the slope of land and shed position.

I've dug channels around the shed and sealed the base of the shed to the concrete so water doesn't enter anymore however the sides of the concrete get slightly damp after prolonged rain.

I have lots of 5mm MDF that I started cutting to size and mounting however the damp has me worried. No water gets in from the roof or top of the walls, I think its under the concrete and wicking through. I was intending to use flashing for the base of the walls which meet the floor.

The walls have 45mm between the outer tin and where the MDF panels will be so I have a few questions:

- Are there tough floor paints (like rubber) that can resist moisture ingress and not chip with dropped tools, offcuts and abuse?
- Can I use the MDF I've got or is it likely to be ruined from the damp? If so, what can I use for the walls?
- Can I use regular batts or do I need to moisture seal them between the MDF and batts? If so, what products should I use?

The roof is also rusting out and I'll be replacing that in a year or two. When I do, is it worth putting batts in? Doesn't the metal insulation reduce heat entry but allows heat exit?

I've done a search and can't find any similar topics so any advice is appreciated.

[crowie]

Firstly; G'Day & Welcome to a top forum.
You'll find a heap of helpful & knowledgeable blokes & ladies on the forum and for most very willing to assist.
Make sure you show off more of your handiwork as everyone loves a photo, especially WIP photos with build notes.
Enjoy the forum.
Enjoy your woodwork/new shed.
Now I'm not sure if this will work but what about the polystyrene foam sheets the builders are using for under floor insulation.
As far as cladding you use a run on mini orb or compressed sheet around the bottom couple of feet then ply, mdf or chipboard around the rest [whatever you can scrounge or get cheaply]....
Don't forget to ventilate the ceiling/roof are to allow the heat to escape, when & if it builds up.
Cheers, crowie

[BobL]

The walls have 45mm between the outer tin and where the MDF panels will be so I have a few questions:
- Are there tough floor paints (like rubber) that can resist moisture ingress and not chip with dropped tools, offcuts and abuse?

Yes there are, you have to shop around and see what there is - too many to detail here.
The floor will need to be VERY dry before you seal and then paint it, ie no rain for 8-10 weeks.
You may need to get some targeted help over in the Renovation forum

- Can I use the MDF I've got or is it likely to be ruined from the damp? If so, what can I use for the walls?

If you have nothing else the MDF would need to be at least painted on both sides as it will suck moisture from everything - in the end it will look terrible
If you have a damp problem, short of ripping up the concrete and laying a damp proof layer it sounds like you will continue to have problems.
If you can get a dry spell to seal the concrete then you might have a chance with MDF but MDF is horrible noxious stuff anyway and I would not use it.

It sounds daggy and unattractive but when you have a damp problem something like corrugated iron or Colorbond would be ideal. The metal work part of my shed is lined in miniorb, (mini corrugated iron) and it looks very classy and sound wise it is very good and I wish I had clad my whole shed in it now.

However, unfortunately it is very expensive.
But if I had a large shed I would not hesitate to insulate it and line it in metal either corrugated or colorbond.

- Can I use regular batts or do I need to moisture seal them between the MDF and batts? If so, what products should I use?

Regular bats will be fine. If you go for

[/QUOTE]The roof is also rusting out and I'll be replacing that in a year or two. When I do, is it worth putting batts in?[/QUOTE]
Definitely

Doesn't the metal insulation reduce heat entry but allows heat exit?

A little maybe - but not much - you need good ventilation (eg at night) to be really able to cool the shed down (or air con )

[Ross]

Shelleys have paint on product for blocking rising and penetrating damp walls and slabs, sorry I can't remember the name.

In the roof I would install 2 whirly thingys they increase the air flow helping removing fine dust and moisture.

Ross

[pmr]

If you have nothing else the MDF would need to be at least painted on both sides as it will suck moisture from everything - in the end it will look terrible
If you have a damp problem, short of ripping up the concrete and laying a damp proof layer it sounds like you will continue to have problems.
If you can get a dry spell to seal the concrete then you might have a chance with MDF but MDF is horrible noxious stuff anyway and I would not use it.

It sounds daggy and unattractive but when you have a damp problem something like corrugated iron or Colorbond would be ideal. The metal work part of my shed is lined in miniorb, (mini corrugated iron) and it looks very classy and sound wise it is very good and I wish I had clad my whole shed in it now.

However, unfortunately it is very expensive.
But if I had a large shed I would not hesitate to insulate it and line it in metal either corrugated or colorbond.

Firstly, your shed looks great and I'm really impressed with the floor color and mild gloss!

Do you do any automotive work in your shed? If so, do you think that color choice for a floor is good?

My choice of MDF is because I have about 40 sheets in the garden shed that would otherwise go to waste (or eBay if it ends up unsuitable) and because I know I'll hit/run into it with wood/metal/whatever I'm working on due to clumsiness so I'd rather a cheap and simple wall.

Regular bats will be fine. If you go for

The roof is also rusting out and I'll be replacing that in a year or two. When I do, is it worth putting batts in?[/QUOTE]
Definitely

A little maybe - but not much - you need good ventilation (eg at night) to be really able to cool the shed down (or air con )[/QUOTE]

I'm going to put an evap cooler in the window. The shed has a problem with dust and I want to keep it sealed when I'm not working in there and when I am, the evap cooler will provide a positive air pressure (and cooling for hot days) to reduce dust settling.

Also, thanks for the warm welcome and I'm a little embarrassed for my first post going in the wrong section

The workshop is a pigsty at the moment because I've removed all the junk cabinets while I rip out the mixture of plasterboard, MDF, chipboard and some manufactured crapwall and refit it properly, I haven't got a photo of before I moved in, this one was yesterday after I'd fitted most of the rear wall.

[BobL]

I don't think evaporative coolers are good for workshops as they rust things up pretty quickly.

If you are using a welder or other dust making thingo you need extraction not over pressuring.

This is what I have for welding - there's a 500 cfm extractor that vents the welding bay in the overhead canopy - in the other half of the shed theres a ducted 1250 cfm dust extractor that vents outside the shed. There's also air con but there's not much point in running it if the extractor or DC are working.


My floor is berger jet dry Heavy Duty. I do a fair bit of metal work and the hot swarf fairly cuts up the paint so I will be recoating every couple of years. I had no say in the colour - SWMBO wanted to have the say on that and I though it was no big deal.

[pmr]

Good point. I didn't think of the corrosion from humid evap cooled air.
Might throw in a small split and a few fans for use when I'm not making dust or smoke.

Thanks for the tip