Ian wrote:
I'm planning to replace the internal doors in my house:

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1. Several of the room doors will be 4-panel 35mm thick. I'm thinking
of the Cadeby wood grain effect range (as sold in B&Q). Two problems:

a. Although most of the doors will be the standard 1981mm high, some
will be significantly shorter, down to 1955mm. I contacted the
supplier, who told me it is only acceptable to shave up to 6mm off
the top and bottom of the doors, otherwise their strength will be
compromised.

Just had a quick look on the B&Q website at this door and I would suggest
that you can cut the door down to the height that you require using a saw
(important), keep the off-cut, carefully remove the remains of the two faces
off the bottom rail (leaving this clean and intact) - and then refit the
bottom rail by applying glue to the original two faces and cramping (or
clamping if you prefer) and skew-screw through the bottom rail into the two
stiles.

b. One door is only 680mm wide, which is not available in this range.

This would be far more difficult to overcome (having to cut around 75mm off
a (presumably) 760mm wide door - so you'll either have to contact the makers
of the door to see if they will do a purpose made one or widen the opening
(if you can or want too) to fit the smallest standard door width.

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2. The remaining doors are for cupboards (cloaks cupboard, general
storage cupboard etc). These need to be plain ply, 25mm thick,
standard height. Problem: all I can find anywhere are doors that are
35mm thick. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If these are essential, then (presuming they are simple flush doors to be
painted) either make them yourself [1] or ask a joinery shop to do it for
you.

Solutions/comments anyone? (The room doors don't necessarily have to
be Cadeby -- we are just looking for substantial 4-panel doors).

[1] Simply make a simple frame of the required thickness, butt jointed
and using glue and corrugated fasteners (wriggle nails) to fix the joints
(don't forget to include a 'lock-block' of sufficient size, and the cut
some thin plywood sheet or hardboard to size and then glue and pin [2] the
sheets to the frame - and finish with the desired decoration.

[2] You can use heavy weights to hold the ply/hardboard until the glue
dries, or use temporary 'tacks' and remove one the glue has tried or simply
glue and nail (punching the nails below the surface) - and then fill and
paint as required.

There may be other and better suggestions, but I hope this is of some help.

Cash