Chalet door design - source or build.

[Agent_zed]

Hi all,

just back from a skiing trip and the door to the Chalet caught my attention. I need a new front door and I like the idea of something similar as I would think it is quite insulating.

It was about 7cm thick and had tongue and groove inside and out and appeared to be plywood in the centre. I am wondering if this sandwiched a core of celotex type material.

I've tried a google search but looking for a french front door doesn't work as it thinks I want French doors.

Anyone know where to source something similar in the UK? I know a company called spitfire makes sandwiched construction wood doors but I think they are about £2000+ I can't find the image now but they used to have a picture of the construction and it is as I've mentioned above. I can't believe the one I saw though was anywhere near as expensive.

The alternative is to make one. I am thinking as above I'd start with a core made with plywood and some cross members and then filled with celotex (20mm). So 9mm - 20mm - 9mm would take it to 38mm. Then 18mm tongue and groove inside (36mm) and out would take it to 74mm thick.

If I was to make one the thing I'm not sure about is how to attach the tongue and groove. Would they be glued or nailed or both? I assume they need some movement for seasonal change so perhaps that wouldn't work?

Another option which I've literally just come across whilst googling for this thread is to buy a door blank like this Solid Core Door Blanks & External Door Blank From Doordeals and use it as the base to attach the tongue and groove etc. Which I guess would hopefully give a good flat base. But not as insulating as having celotex core.

Any thoughts?

 

[niall Y]

On one job I worked on, the door was supplied framed. ledged and braced. It then had a breathable membrane fitted and stapled to the contours of the back . Celotex was then fitted in the recess formed by the frame, and T&G was nailed to the back, completing the sandwich. This seemed to work quite well, though the doorframe has to be able to accommodate the extra thickness.

 

[Agent_zed]

doh, forgot to add the photos

 

[Agent_zed]

On one job I worked on, the door was supplied framed. ledged and braced. It then had a breathable membrane fitted and stapled to the contours of the back . Celotex was then fitted in the recess formed by the frame, and T&G was nailed to the back, completing the sandwich. This seemed to work quite well, though the doorframe has to be able to accommodate the extra thickness.

Ah yes I see. I guess the thing I'd be concerned about is me being able to make the L+B door that is perfectly flat to start with. I'm thinking plywood with bracing can be done on a perfectly flat floor.

Re the thickness, the way they did it on the door in question was to use hinges that were on the outside of the frame. The central door was still only a 40mm door recess with the extra width sticking further out into the frame hole and rearward it came out past the frame. if that makes sense. You can hopefully see on the pic the tongue and groove is not within the frame and the hinges are just visible.

 

[alex robinson]

I have recently made some insulated double doors for a shed. Much cruder than for a house, but an osb internal skin gave a very simple box of 2x4 a lot of stiffness. Built on a flat concrete floor. 100mm insulation made finding suitable hinges difficult and the middle where the 2 doors meet had to be angled otherwise they would have jammed.

 

[imageel]

As you've discovered doors and frames to suit those kind of dimensions are not cheap, but if you make them yourself you'll save a lot of cash.

For my workshop built 13y ago I was concerned about noise insulation and as I had some 170 x 47 lengths of joists left over I used them to construct the doors, approx 80mm thick and in-filled with Celotex. I lipped the doors with left over Sapele and used that too to build up the frames/reveals as laminates as I didn't at that time have access to a spindle moulder or tooling to machine such large sections up.

 

[niall Y]

Ah, as I understand it now.... The hinges with their knuckles just visible would have to be something midway between an ordinary butt hinge and a parliament hinge otherwise the screws could easily coincide with the join between the t & g and the frame.

The horizontal t & g to the outside seems to be rebated to allow the door to sit further back into the frame. There seems to be another layer in there, just behind the back t & g which is probably in lieu of any diagonal bracing and is a flat board with wood edging to the sides . The t & g looks to have been secret screwed or they have used special clips. There might well be a central vertical upright in the frame which will also give a central fixing point for the outside t & g

The window frame seems to be two separate halves, front and back, with the glass sandwiched between the two.

There looks to be enough information here to be able to fabricate a similar door. So, as I see it there is a basic rectangular frame with a vertical upright and a board to the inside with a hole for the window. There is probably a horizontal rail in there as well just under the window. There will then be insulation covered with a breathable membrane, and then the outside and inside t &g will be applied. One thing to bear in mind is that you need sufficient 'meat' on the frame to take the screws for the hinges and the lock.
Best of luck Niall

 

[simonridout]

I have just made some doors for my workshop, each 210 X 106 cm, two sheets of 11mm OSB separated by 50 X 50 mm wood, around the edge and as back up to hinges, bolts etc, the remainder of the sandwich filled with 50 mm rockwool. Works well, using bolt on barn door type hinges. Heavy, so needed a strong frame, well tied to the structure.

A previous pair of garage door had a frame reinforced with a giant ‘capital E’ made of 80 X 6 mm steel strip, welded, to prevent sag and provide backing for hinges, locks etc. No sag but some warp, easily corrected by top and bottom vertical sliding bolts on the first door to be closed and a storm flap on the second.

 

[Doug71]

Ah, as I understand it now.... The hinges with their knuckles just visible would have to be something midway between an ordinary butt hinge and a parliament hinge otherwise the screws could easily coincide with the join between the t & g and the frame.

I recently made a thick door by using a door blank clad on both sides with MDF, I used projection hinges so the screws went into the solid door edge rather than the edge of the MDF.

Something like these

https://www.doorhandlecompany.co.uk...NzHDXjRzwqYP_9eBQD6ean126RAOHflBoCT7oQAvD_BwE

 

[HOJ]

On the basis @Agent_zed you are talking about a front door for a house, I would suggest your "Spitfire" door @ £2k is a bit optimistic, + they are a mix of materials with an aluminium sub frame, as are Urban Fronts doors, which IIRC are about £5K.

This is an snapshot of UF principal method of construction which I would suggest is similar as to how Spitfire make theirs:





This is a link to an old thread: Door from @murdoch who made a door with a celotex and timber sandwich.


Another option as a supplier and for info is Doormaker

 

[Agent_zed]

I'm thinking through various ideas and I wonder if a good method could be buying one of the door blanks I linked above and then cutting out sections leaving a web like structure. Then filling the gaps with celotex and then boxing in with the tongue and groove.

The advantage as I see it would be starting with a perfectly flat (assuming the door blank is flat) structure. If I were to make the door from sections then I'd have to make sure it was perfectly flat and risk it warping.

What I don't know is how to attach the boards. If I glue them entirely on will that work? or does it need movement?