Garage Door Insulation - Condensation on foil tape

8 Jun 2020
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United Kingdom
I have added xtratherm insulation boards to the back of our garage doors to help keep some heat in the garage.

This morning I went out to have a nosey and noticed some condensation on the foil tape. It is specifically sitting on the tape stuck to the garage door metal.

Obviously it got very cold last night and the heat from the boiler (lives in the garage) meeting the cold surface of the metal has caused the condensation.

I’m hoping to add some form of cladding over the insulation for cosmetic purposes. Any form of wood sheeting would likely go mouldy with moisture in behind it.

Is there anyway to address this?


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The reason it's only on the tape is that is uninsulated so a cold surface. It suggests to me your garage is humid, perhaps lacks ventilation ?
Do you have a humidity source in there, tumble dryer, clothes line ?
You might benefit from a dehumidifier (one that can deal with low temperatures).
No machines running in the garage bar the boiler. No clothing lines either. I will put my humidity sensor in there to see what level it’s currently at.
I could probably fill the metal channels in the triangle shape with expanding foam to help insulate. Metal round the edge of the door just sits on the frame so not much I can do with it.
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The tape is applied over where the door is reinforced with metal, the metal will allow cold to be conducted straight through the door and insulation, to the tape. The result is that any moisture will condense on the tape.

The only way to avoid that, will be to add an extra layer of insulation over the top, of where the tape is.

What are you using the garage space for?
You may have to add a strip of insulation over the cold bars, it was 0 degrees here last night, anything much over 55% will condense in that. Have you checked for water leaks around the boiler, any damp patches on the ceiling, using it as a gym with to much heavy breathing etc ?
Garage is very dry. There is an absolute ton of wood in there for various projects. Perhaps there’s a lot of moisture coming out of it as it dries out.
@Harry Bloomfield at the moment it is used as a workshop (very much an amateur).

This will likely progress into a ‘man cave’/workshop. I understand that if I want it to become a proper room it would be best to put up stud walls and seal the doors off completely. I like having the doors there so I can bring the cars in to work on them if needs be.
Garage is very dry. There is an absolute ton of wood in there for various projects. Perhaps there’s a lot of moisture coming out of it as it dries out.

Is there a special reason to try to retain heat/keep the garage warm?
@fourtytwo that wasn’t the intention but there’s been a fence worth of wood panels in there for 18 months!
Would just like it to be warmer when I’m working in there. Will be adding some heaters in the next few weeks as well.

Another layer of something like the above be completely overkill?

Maybe best I just run some thin strips over the cold metal surfaces.

Thanks for the input.

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