On Thu, 11 Jun 2009 11:04:41 +0000, Stuart Noble wrote:

Jules wrote:
On Wed, 10 Jun 2009 14:53:49 +0000, Stuart Noble wrote:
Worth that just to avoid the d-i-y scenario whereby it's supper time and
we still don't have a working back door.

:-) I replaced our front door a few weeks ago, which was quite a hassle as
our house wasn't built when they had any particular standards - so all
modern doors are a bit higher than the opening (width-wise it was OK,
thankfully).

Was this what they call a pre hung door with its own frame etc?

Yep. Just a cheapy job, nothing fancy - I'm banking on replacing it with
something nicer in a few years. One of the kids managed to break some of
the glass in the old door, and as that one had seen better days anyway it
was a case of rushing out and buying a replacement quickly.

All went well, but making an opening taller whilst keeping things
structurally sound and not destroying half the walls seems to be
something of an art.

The art of staying below the lintel :-)

I ended up taking some height out of the lintel (which was a
pair of 2x6's), but had enough space to add more material and make
it thicker, which should help. It won't be as strong as it was, and I'd
definitely have done something else if there was a storey above to
support, but I'm confident it'll be enough for what it needs to do
(flat roof above, snow weight in Winter, someone occasionally walking up
there to do DIY stuff etc.)

We put in a new door at the brother-in-law's place last weekend, and that
one was interesting; at some point in the past someone had taken out
material below the door frame to make the old door and frame fit - which
is perhaps not unreasonable, except they'd done it with a chisel by the
looks of it (or possibly with their teeth :-) so that nothing at all down
there was straight or level any more. We ended up putting in a whole new
bunch of support-work just to get things nice and flat and provide a
base for the new door/frame.

Height is my problem too. By
knocking the plaster off I can see what I assume is the bottom edge of a
wooden lintel above the existing frame, so in theory the top of the aly
could be fixed to the underside of that, leaving me 30mm to play with at
the bottom. I gather this should be a sill of some kind so that the
drainage slots in the frame empty on to a sloping surface.

Hmm, well 30mm sounds like it might be enough for a wooden sill/step,
just... although I expect you can buy aluminium ones pretty cheaply which
will have a much lower profile (the door I got has one which can't be
more than 20mm in height) - or maybe you can source one at a suitable
junkyard / recyclers (or via local Freecycle list) from a door that
someone's dumped.

With the
sides it seems you don't know what wooden framing you need until you've
knocked the old one out. Maybe I'll take out a small cross section to
get the profile of the brickwork. I'm beginning to see the advantage of
upvc doors where framing isn't an issue.

I think the typical approach is to rip everything out that's related
to the old door and its frame, measure, buy a new door that's as close
as possible to the available width - then do whatever work's necessary to
the opening to get the height right, put new door/frame in and shim out as
needed, insulate any gaps, then add trim (and seal up) to hide all the
grotty-looking stuff.

Given that you have the door, taking a cross-section seems like a good
idea and will allow you to assemble some likely materials for a frame -
then it shouldn't take too long when it comes to it to make something
functional. Adding the bits to make it look pretty can come later...

cheers

Jules