Cutting down Doors - Proportion

Pont

I'm re-fitting doors in my house. These are the doors:-

http://www.diy.com/nav/build/doors/internal-doors/4_panel/4-Panel-Knotty-Pine-Internal-Door-9273982?skuId=9283679

They need to be cut down by 140mm for my upstairs as the bedrooms/bathroom doors are cut into the eaves. The top strut measures 80mm in depth and the bottom strut measures 140mm in depth. I can't work out what needs to be cut off from the top and from the bottom for it to look in proportion.

My calculations are 80 + 140 = 220mm divided by 140mm (off) = 1.57mm

Therefore 80mm divided by 1.57mm = 50.9mm (50mm = 5cm)
And 140mm divided by 1.57mm = 89.1mm (90mm =9cm)

Do you think 5cm from the top and 9cm from the bottom will look 'right'? I'm working it out mathematically rather than working it out as a carpenter/joiner!

Views and opinions greatly received!

tony6403

That is rather a lot to cut from a mass produced door.
Check the packaging which will probably tell you the maximum amounts that you can remove without affecting the strength of the doors.

-taff

If it's a solid wood door, you can cut off what you like.
People don't look at the bottom of doors, only eye level, so roughly proprtionate will be fine.

Pont

tony6403 wrote: »

That is rather a lot to cut from a mass produced door.
Check the packaging which will probably tell you the maximum amounts that you can remove without affecting the stength of the doors.

I understood that as they are solid wood it's doable as taff suggests.

DirectDebacle

Doable. Certainly. Will the door be usable? Possibly.

Best way to join a rail (top strut) and stile (side strut) for a door is by mortice and tenon. Removing the amount of material you plan is going to seriously weaken the joint.

That is presuming mortice and tenon joints have been used. If the joints have been dowelled then weakness will be even further increased.

As said check with the manufacturer.

leveller2911

Pont wrote: »

Do you think 5cm from the top and 9cm from the bottom will look 'right'? I'm
working it out mathematically rather than working it out as a
carpenter/joiner!





Views and opinions greatly received!

I wouldn't worry about whether or not it looks right .

If your taking off 50mm from the top rail which is only 80mm to start with and 90mm off the bottom rail I will wager my entire lifes savings that the door will "drop" (fall out of square) and literally fall apart.

IIRC those doors are not morticed and tenoned but have 2 dowels instead glued into the rails and stiles.Its the timber thats left above and below the dowels/tenons that stop the door falling apart.The fitting instructions probably say you can only take a maximum of something like 5mm of each side and 10mm off the height, this is for the exact reason I mentioned.

Even if they were morticed and tenoned it would drop so its a non starter IMO.

olias

If you are a decent diyer, there are all sorts of ways to re strengthen the joint if you cut off the dowel or most of the tenon. Using something like a router (or even drill and chisel), you could let in a tongue across the joint at the top or bottom where it wouldn't be seen for example. You could also use extra long countersunk screws through the joint from the side and fill/cover before staining or finishing. Lots of options.

Olias

leveller2911

olias wrote: »

If you are a decent diyer, there are all sorts of ways to re strengthen the joint if you cut off the dowel or most of the tenon. Using something like a router (or even drill and chisel), you could let in a tongue across the joint at the top or bottom where it wouldn't be seen for example. You could also use extra long countersunk screws through the joint from the side and fill/cover before staining or finishing. Lots of options.

Olias

If the OP cuts down the door as he intends he will have a 30mm (1.25")wide top rail and a 50mm (2")wide bottom rail....... No strength left and nothing to keep the door from dropping out of square. Even long screws won't work because the weight of the door will break the timber around the screws...

Theres a good reason why they make the door with an 80mm top rail and 140mm wide bottom rail and that its anything narrower and the door will drop and they will be replacing customers doors FOC.

Its a non starter IMO but what do I know................

olias

I hear what you're saying - but its a £30 budget door (or several of them). Presumably the OP doesn't have the cash to spend hundreds on custom doors. I still maintain that with a combination of strengthening, he could overcome any prblem in weakening the joint. It is after all an upstairs domestic installation, and is unlikely to be subject to much abuse.

Olias

Pont

Oh gawd - what have I started?!

'He' is a 'she' btw (not that it matters).

leveller2911

Pont wrote: »

Oh gawd - what have I started?!

'He' is a 'she' btw (not that it matters).

Ooops .........sorry ,I usually post "The OP" rather than he/she...

Don't worry Olias and I haven't fallen out, just difference of opinion..

EDIT:If you really want to go down the route of using those doors then a carpenter would be able to de construct the door by taking off the top rail(drilling out the dowel tenons), cutting down the panels (height) and muntin (central vertical timber) and re-fitting the top rail.

This will keep the doors strength by not taking anything off the width of the top rail/bottom rail.Its a mornings work so budget about £100-00 max .I know its a lot compared to the price of the door but it would be worth it.

Aesthetically it may look better by moving the top rail down and bottom rail up, this would keep the panels looking in proportion rather than just moving the top rail lower.