Exterior doors are big and heavy, because they are directly exposed
to whatever the weather brings; and in Britain what it brings
most often is rain. So whether you go for a uPVC/metal door, or
a wooden one, it's likely to be expensive. The good thing about
uPVC doors is that the door and frame are typically supplied as
a unit, so fitting the door in the frame is relatively straightforward.
With a wooden door, even if the door and the frame are nominally the
same size, you'll generally have to trim the door to make a proper fit.
The problem with uPVC doors is that, well, they're ugly. What's more, they
don't look very Victorian.
Having said that, I think if I were doing this job again, and knew what
a trial hanging the door was going to turn out to be, I would probably
opt for a uPVC door with metal frame. However, I was fortunate enough
to be given a door which was in good condition, and a saving of
a couple of hundred quid is not to be sniffed at.
Incidentally, as I found out on an earlier job, hanging a second-hand door
that is warped, badly painted, or somewhat rotten is just not worth the
effort. Any money you save will be offset by an enormous investment in time
hanging it.
With a uPVC door, most of what follows is completely irrelevant; I am
writing now about the specifics of hanging a hardwood door.
Hanging
Unless you're very lucky, the door you have will not fit perfectly in
the frame. Doors are usually supplied a tad over-size anyway, in the
expectation that you will trim them. And even if that isn't the case,
by the time the brickwork has settled and you've pulled it around fitting
the roof, the door frame will likely no longer be a perfect rectangle.
I found, for example, that by the time I came to hang the door, the
frame was about 5mm narrower in the middle than at the top and the
bottom, and the left-hand end of the door cill was about 5mm lower
than the right. I'm sure the frame started off perfectly level and
perfectly rectangular -- but mortar is slighly plastic for
quite a while after use. These errors -- a few millimetres here and
there -- are easy enough to deal with. You just need to offer up
the door into the frame, mark where it's touching, and set to
work with a plane.
The complication is that an exterior door is seriously heavy, and
if you're working on your own, by the time you've lifted it in and
out of the frame a few dozen times, you'll be ready to saw a big strip
off all the way round. That would be a mistake, because the
weather-proofing of a door depends on it being a really close fit
in the frame. By the way -- a hardwood door will swell slightly in
damp weather, so you either need to allow it time to acclimatize
before hanging it, or allow a little swelling room in the final size.
The actual installation of the hinges and placement of the door
is pretty standard practice, so I'm not going to describe it in
detail here. I found when I got the door on the hinges that I had
cut the hinge rebates too deep (I always do this), so the door
would not close (well, not without leaning on it, anyway). So I
had to unscrew the hinges and install thin slivers of plastic
as shims underneath them. I find that I end up doing this every time
I hang a door -- you'd think I'd have got the hang of it by now.
Exterior doors are usually supplied with a wooden lip for the bottom,
the purpose of which is to deflect rain away from the gap between the bottom
of the door and the frame. If you're careful, placement of the
lip will also reduce the visibility of an uneven gap between the bottom
of the door and the frame, caused by the frame being slightly
out of square.
Door furniture
You may be tempted to think that, when the door is hanging on its
hinges, that's the bulk of the job done. Not so: you've still got the
door furniture -- locks, letterbox, handles, etc. to install.
Installing a lock with decent security is not easy. I used and ordinary,
Yale-type cyliner lock, which at least has the advantage that most of
the lock mechanism is bolted to the back of the door, not installed inside
it. But you still need to cut a large hole for the cyliner (barrrel) to
fit into, and this has to be done with some precision because the
cylinder bezel will only hide a small amount of mis-cutting.
You might find that it's best to leave the installation of the lock
until the door is actually swinging properly on its hinges because, once
it is, you might find that you need to plane a bit off the non-hinge
edge to get an exact fit. And if you've already drilled out the lock
holes and rebates, they'll be in the wrong place. However, cutting a
hole for the letterbox is much easier to do before the door is hanging,
and its location is not that critical.
The positioning of other door furniture such a knocker, handle,
house numbers, and so on, is not critical either. But, if you leave
this job until the end, you might be able to place them such as
to hide any minor dents or bruises you've made in the door while you've
been dragging it in and out of its frame. I did, anyway.
Finishing off
Hardwood doors are pretty robust, but they still need to be oiled
or varnished after hanging to get decent water resistance. Even if
you buy a pre-finished door, you'll still have to oil or varnish
on the edges you've planed, and any other place that is showing bare
wood. The door frame and cill will also need to be painted or
varnished. In my opinion, varnish works better than paint for
cills, because it doesn't show the muddy bootmarks so badly.
Since I was expecting to have to varnish the porch floor anyway,
I did the cill at the same time.