condensation in a 40ft container

[squazy84]

i have a 40 ft container for storage and at this time of year there are always condensed droplets of water on the roof, i want to stop this as it causes corrosion to anything i have stored, i was going to insulate the upper surface with http://cgi.ebay.co.uk/50-SQM-DOUBLE...737?pt=LH_DefaultDomain_3&hash=item3a61407a51 or similar stuck to the ceiling with mastic sealant or similar, will this work,or is there a better way,ventilation ect,thers a few accomplished guys on here so i figured i might as well ask and save mysel the trial and error method lol

 

[decepticon]

i fixed a 100mm spacer along the eaves of the roof and 200mm spacer to the other side and fix metal corrugated sheets to the spacers with fibreglass quilt to the void.
probably more expensive but it cured the problem on my container.
take the fly mesh off the air vents and drill holes bigger for more ventilation
cheers

 

[brightspark]

either polysyrene tiles or sheet stuck on and good ventilation

 

[squazy84]

i fixed a 100mm spacer along the eaves of the roof and 200mm spacer to the other side and fix metal corrugated sheets to the spacers with fibreglass quilt to the void.
probably more expensive but it cured the problem on my container.
take the fly mesh off the air vents and drill holes bigger for more ventilation
cheers

yes the holes are soon to be replaced with shower ventilators or similar,you did a false roof and filled the cavity with insulation is that what you did?

 

[decepticon]

new roof on top of the container with good over hangs to keep some of the rain off the sides to prevent a bit of rusting and fibreglass insulation.
trouble with the roll you linked to is that the moist air travels through the joints and will still condensate.
rigid insulation sheets will do but roof will need to be dry for adhesive to work sucessefully and all joint and ends need sealing to stop the moist air condensating on the roof above the boards

 

[Mikey D]

i rent a storage container , the roof is spray foamed does the job well .
you would need a specialist contractor in to do it tho .
cheers mike

 

[squazy84]

oh yes i was going to wait till the roof is dry and wipe it clean with solvent then us a mastic gun to apply a bead of sealant adhesive to prevent the ingress of moisture between the layer of insulation and the roof, as far as i understand the moisture in the air condenses on the cold steel surface so i have to install a barrier to this air?

 

[the snooper]

my mate had his narrow boat insulated they come down and used spray foam
to cover the entire sections of the interior then replaced the paneling you could maybe use that method if its cost effective

 

[Omniata]

The spray foam is an excellent answer to the problem...

I designed one of the available mixes for canal boats and as long as it's applied properly it leaves no gaps, so no room for condensation...
It's fire proof as well

 

[decepticon]

spray foam would sort the problem but it such a messy job and looks awful when finished and you will need to empty unit before application i would have thought
specialist contractors = ££££

 

[Shox Dr]

I would have said the cost in Spay foam is the setup and cleaning of the gun. I'm on a site at the moment where they had a 10x40mtr portal frame building roof coated cost was £2.5k
So not a lot.


What you have to remember is insulating a building does not get rid of the problem it merely moves it, to another cold surface. Get rid of the water and you won't have a problem in the first place

 

[cumbriasteve]

My steel garage roof was the same and I did loads of research, it will only work if you can prevent the air reaching the cold surface to form as condensation.
The roof lining in a car works the same, without it you would be sitting under drops of condensation on frosty days.
My solution was to use foil backed plasterboard and sealed around the edges and joints with a cheap £ shop sealant..leave a couple of mm to allow it to squeeze right in the gap, I got 10 sheets of board for £80 from my local builders merchant.
I also filled the void with rockwool...the effects are, totally bone dry and a fair amount of sound proofing noticed, well worth doing because with the weather we have now I would have ben wearing waders to get in the garage.

 

[Emmsy]

cant you just celotex the interior?

 

[astro_al]

Hi, I sprayed my workshop roof with spray foam myself, pic below of 2 sections done.

The foam worked out at about 7k+ I think for a 40m x 20m area (corrugated, so it uses much more).

Its a grotty job, but worthwhile - especially for a small area.

It'll drip down while spraying, so make sure everything is covered / removed below.

Condensation now only drips from the non-insulated window panels. Its a bit warmer too.

Ages ago I had my narrowboat sprayed too and in a small space like that it made a hell of a big difference. Its good stuff.

Al.

 

[pidgeon chit welder]

Hi, I sprayed my workshop roof with spray foam myself, pic below of 2 sections done.

The foam worked out at about 7k+ I think for a 40m x 20m area (corrugated, so it uses much more).

Its a grotty job, but worthwhile - especially for a small area.

It'll drip down while spraying, so make sure everything is covered / removed below.

Condensation now only drips from the non-insulated window panels. Its a bit warmer too.

Ages ago I had my narrowboat sprayed too and in a small space like that it made a hell of a big difference. Its good stuff.

Al.

Al

Perhaps you should have double skinned the windows with translucent panels like I did using 3 inch x 3 inch blocks of wood and sealed them around the edges during the putting on the 4 inch overall coat .. you can also do it retrospectively of you want to .

It helps keep it cooler in summer as well.

 

[astro_al]

Yeah - good suggestion, I might look at doing that next year.

Al.

 

[Ratty]

oh yes i was going to wait till the roof is dry and wipe it clean with solvent ..

A lot of PU adhesives actually need some moisture to cure so a slightly damp surface is an advantage.
This is an example but I've bought cheaper stuff and it all works pretty much the same and will stick well to steel.

 

[IanO'Cov]

Hi, I have the same problem in my large sectional concrete garage and run a dehumidifier. Problems are that you need to seal from outside air which has high humidity. Don't have the door open when working in there and remember to empty the water storage bottle or pipe it into a larger storage or pipe it to outside, a bit of garden hose will do. If you have door open when working it will get rid of moisture once it is locked up and sealed. They work on the fridge principle so wont work when freezing conditions. I just turn it off when freezing and back on when it warms up. All my machinery and tooling used to be covered in moisture when humid weather but I don't have a problem now. Mine cost £50 second hand. If you use a gas heater they produce water so make the problem worse. If it doesn't work for you, you can sell the unit on.

 

[the snooper]

the only problem with de-humidifiers is its an ongoing cost to run them insulation is the way to go its cheaper in the long run