Garage door mods

[MarkyG82]

My up and over door is cold and drafty thin metal (steel?).  The skin is in 2 pieces, so I have a plan to pull it apart and rebuild the pair of skins into individual doors with an insulated core.  This will then have seals around the edges to limit the drafts etc.  The second door (double garage) will be blocked off on the inside as we dont use that anyway.

Mechanically I am fine designing and building a custom frame and door to mount the skins to, which will be glued (with sealant) and screwed to said door blanks. 

I plan to fill the void with insulation.  Question is what type?  And how to layer it?  Do I go with cheap loft insulation or panels and should it be kept away from the steel skin?  How I insulate it will inform the design of the door.  Mainly the thickness.

Construction of the door may or may not include a diagonal brace depending on how much I trust the front and back face to keep it square. SO the insulation may need cutting.  Thats no big deal but again may inform the materials used.

 

Thanks in advance.

[MarkyG82]

So I'm either an numpty for planning this or asking the wrong question 😉

[saveasteading]

On 18/01/2023 at 15:19, MarkyG82 said:

Question is what type?

I normally caution against the use of expanding foam. But it seems ideal for this as it will save so much work in dismantling, and reassembling.

 

I would drill lots of holes on the inside, (300mm centres?) just big enough for the nozzle, and start squirting. It will emerge from adjacent holes, and possibly be very messy, so cover the floor, have lots of wipes and a bucket,  and wear gloves. After a few, you should get the hang of the squirt length.

If you leave a few gaps it won't matter, as i bet there is a lot of air round the sides. Anyway, there will still be cold bridges to the perimeter and some cross braces.

 

The alternative is to fix insulation on the inside. Will that work without clashing with the mechanism?

I wouldn't take the door apart.

[Kelvin]

Injecting foam into it will make next to no difference though. If you can figure out a way to insulate the back of it without taking it apart I’d do that. Improving the airtightness will be quite difficult though. 

Edited January 20, 2023 by Kelvin

[MarkyG82]

So it seems I did leave some critical info out. The reason for taking the door apart is to convert the single up and over to a pair of side opening doors.  Reusing the skin will help maintain the style similar to the other door. I will build a doorframe and a pair of door skeletons on which the skins will be fitted. Then filled with some sort of insulation and a rear skin added. I can design in plenty of seals to help with cold bridging and drafts.  Soundproofing will be a happy side effect.

 

Hopefully that gives a better idea of what I'm trying to achieve. Also plan to fit a multipoint lock like in a front door. Should be able to build it for about £300 and be better performing than a door 3x the price.

 

Expanding foam sounds like a good starting point. The main issue I can think of is condensation on the inside of the outer metal skin. The adhesion of the foam might help combat this and also be a bit waterproof at least against major ingress.

 

Thanks for the responses btw.

[PeterW]

The stuff they insulate camper vans is good - its a stick on foam and you can build it up in layers so do gaps between ribs and then go over the top. It also helps with sound deadening too. Plenty of it about and on eBay - look for Dodo foam.