Celotex on wooden garage doors

Jan 13, 2022 Last reply: 4 years ago 27 Replies

I spend quite a lot of time in my workshop cum garage that is attched to the house. I wanted to make it warmer in the winter and a couple of years ago I fitted 2" thick Celotex panels on the inside of the wooden doors. This improved the temperature quite a lot.



However. I have noticed that the paint on the outside of the garage door has started to peel off earlier than I would have expected and it made me wonder if that issue was related to the insulation and moidture.



I removed the panels to see ifthere was a buildup of mould on the insdie of the door caused by moisture but there was none. It's a North facing door so there is no prospect of the wood getting overheated by the sun .



Should I remove the Celotex and use soemthing else?



Any ideas?


Celotex normally has a foil face on at least one side - typically both, so should be a good vapour barrier. This should stop warm wet air getting through the insulation where it would have a chance to condense when it meets the cold wood. It would be worth sealing the cut edges of the insulation boards, and also making sure their are no air gaps between the insulation and the timber at the edges.

Similar to when you dry line a solid wall:

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That linked page is excellent and clearly explains the "why" of something I've often wondered. Simples! when you know.

I have been digging through the insulation advice for my current project! Existing single dense concrete block walls with no dpc! Size about 5m x

3m.

The objective is to create a combined Ladies/Gents/Disabled toilet block with shared hand washing. (for people visiting/working in my light industrial/storage units)

I'll probably cheat and purchase the partitions from a specialist supplier but first I need to fit an insulated ceiling, insulate and screed the floor and then sort out the walls after moving and enlarging the entrance door! I may be gone some time:-)

Luckily there is an existing working single place toilet.

To impress the planners I need to get this up to at least an EPC rating of E by 2023 and band B by 2030!

I also need to explore air source heating.

So the conclusion I take from that is that if the insulation has a fouil front skin ( which my Celotex has) then it's Ok becaus ethe mositur cannot get into the insulation. And to take it one stage further, I will use gaffer tape over the edges and joins to stop mpoisture getting in behind.

Come to think of it, I could even put a sauna or hot tub in there if I get it right!

It is likely that the wood is now simply colder due to lack of heatloss

Can't fix that and have the insulation.

"Air source heating" . My advice is think about it again, then again and later stop thinking about it. Not worth the money!

No. Use the foil tape specified for that

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Why not?

The electrical dept. won't like most forms of direct heating in a

*bathroom* type area. Underfloor is practical but will not get me any brownie points with town planning. I was hoping there might be a small wall hung fan unit.

I have found it wise to clean the foil surface (Meths or similar) before taping. There may be a release agent left on the insulation foil surface.

yes, there in fact is..aircon for summer and heating for winter - a hot air blower thing..friends have one.

This sort of s*it

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They say its really good for getting their living room up to temp from cold when the gas CH takes too long.

This is a toilet, not a shower block? I don't think there would be a moisture problem with a toilet, assuming the unit is not on the floor where people can splash water into it.

How about an air to air unit, something like:

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(kind of at the bottom of the barrel in the quality stakes - they go upwards from there)

Theo

It was one that was in the FAQ but not the wiki - it's only when I was trawling through looking for stuff that was worth importing the other day I found that and thought it was rather a good explanation. So I redid the ASCII art to tart it up, but other than that take no credit for it.

For small/medium outbuildings where the only realistic option is electric heating, a heat pump aircon unit can be vastly preferable to resistive heating. The difference in equipment costs would vanish in the first year I would expect.

I'd not have thought this was the cause, more likely some problem with the paint preparation or naff paint. I had some wooden window sills done in black gloss but one has started to crack, whereas the other has not. Difference? both prepared the same, but two different tins of paint. This was black paint so even hough it faced ne it did get quite warm for a few hours in the summer, but not excessively so. Paint can be funny stuff, and wood of course can change shape and size with moisture if water can get in anywhere. My old wood back door used to jam in the winter!

Brian

dew point is now just under the paint....

It's looking a lot better, thanks for taking the time.

Small suggestion - any chance of a more complete contents page? For example, from the Collins DIY Manual:

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With the bonus of potentially structuring the content for a book :-)

Several in there look suitable. 2kW split unit estimated annual consumption 120 units for around £550.

Thanks.

OK Theo. URL saved. Planning here takes about 12 weeks so I am at the gathering info stage.

You get some of those automatically... A full index is here:

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A list of categories:

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Then you can dive into individual categories, e.g:

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(the first two are linked to in the side bar)

There is also a small curated set of links at the top of the home page - that could be added to a bit.

The quality of the category pages does depend a bit on what categories the article writers / maintainers decide to include them in. We could probably do with fewer categories and a bit more organisation. So if you fancy tweaking some, be my guest... :-)

(one can also add to the auto generated category pages to include an intro and links - that can also include pictures - so some of those could be tarted up a bit)

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