how large a hole shall i knock in an external wall for french doors?

Question

i haven't yet bought the french doors however my girlfriend informed me that if i get standard size doors they are much cheaper. As i am creating the hole in the wall myself i feel this is the best option (if anyone can recommend any good UK sites for cheap french doors, be much appreciated). I am going to support the wall with two RSJs and was wondering how large the hole was required to be? is clearance required around the doorframe and fi so how much? also advice on purchasing doors required

Answer 1

Changing the exterior of a building would typically require planning permission. You may also need to submit a building warrant application for the work - things to look out for are typically with regards to insulative properties of the new french doors and energy conservation (what type of glazing, its overall U-value, etc.). You'll also be asked to produce details to show that your proposals are in line with the building regs. Call up your local council to confirm. It's best to keep it legal as it would complicate any possible sale or transfer of the property in the future.

That sorted, you'd best find out the size of the doors you're going to fit as the others have suggested. It's pretty much common sense - you don't want to knock an opening too small or the doors won't fit, and you don't want to knock an opening too large or you'll have another job with filling in the gap.

That said, it's best to make an opening slightly larger that the overall dimensions of the door itself (with the frame of course). Leave about 20-30mm either side and above so that you can adjust the position of the door with packers to achieve the correct setting out and levels. Make sure to pack out the gap left with insulation.

You'll also need to be carefult to use sufficient pinning of the wall above the intended opening to ensure that the whole wall doesn't collapse when you're knocking the door opening. Make sure that the RSJ or whatever you're using as lintol has sufficient bearing on either side, typically 150mm on brickwork.

I'm sure you're aware of the need to lap DPC around the opening to seal against water ingress.

Answer 2

Wickes French Doors External

Answer 3

Normally, when you frame doors, you need to cut back enough to allow room for working as you'll be installing studs on both sides and a header across the top. So, really, you'll want an opening a few inches wider than your final framing dimensions so you'll have room to get a nailgun or hammer in on the outsides (when you nail into a header for example).

Now, I understand you're in the UK, so I'm not aware of UK building practices (I'm in the USA). However, with French doors, it's all pretty easy. Locate a manufacturer and get the dimensions from them. The good thing about French doors is that you don't need to allow space when framing for the facing, as the doors come in their own frame. You only need enough gap to shim on the sides and top basically.

I'm listing some links on French door framing as well as some suppliers in the UK. The important thing to remember is to knock as small a hole in your wall as you can get away with. Get the dimensions of the doors you want, and knock out a hole that big plus 6-12 inches on either side so you have room to work. Take into consideration what your interiors and exteriors are, i.e. rock, brick, paneling, sheetrock, etc. and think ahead about what you'll need to do to add support for those surfaces when covering up around the framing job you do. It may make more sense to knock a hole with a couple feet on either side if you have to work with brick and mortar, know what I mean?

Good luck with your project.

Answer 4

i would buy the doors first so they can be put straight in. I would also recommend you to prop up the ceiling with acrrow props, with a scafold plank on top to hold the ceiling up . or you will possibly have two rooms nocked into one and if you have cavity walls cut out the hole for the rsjs first placing the rsj in the hole straight away and bick it up to take the weight of the wall above then do the same to the other side.

if it is a solid wall take half out and place rsj in brick it up and then do the same to the other halft hen you can take out the wall that is under thr rsj safly with the wall above suported think saftey and you should be ok

Answer 5

definitely buy the doors first , and the instructions with the door will tell you what size rough in you require it is usually about 2 - 3 inches wider and 1-2 inches shorter than the opening this space is filled in with shims when you attach the door in its frame to the opening using Tapcon screws I am in Canada so these screws are a brand we use here I am sure you will have similar ones where ever you are , you always keep the door in it`s frame for this or the door may not close after it is installed then fill in the space around the door with spray in insulation and casing .

Answer 6

the standard height is 2100 by 1200 or 1500 they dont want to be any wider .do NOT USE 2 rsj unless the outside of house is rendered they make lintols for this purpose ..question..whitch way do the floor joist run ?.if they run into the wall its not too bad ..you willneed two acrow props and a plank to carry the weight ..if not leave it alone .youcan do more harm than good ..it really isnot a job for an ameteur.. .trust me on this ..i have been a builder for forty years

Answer 7

Standard doors from B&Q are less than £200 and are about 1220 x 2030mm. Add 10mm to overall w + h size for fitting, Don't forget the cill which is about 30mm to add to the frame height. Also use 6 or 8, 100mm x 10mm fixings, 2 tubes of low modulous silicone, to seal. Must use Low 'E' glass, ie pilkington 'K', and get a certificate of compliance from your local council,

hope this helps

Answer 8

B&Q do good deals on std size doors for the hole hire a diamond cutter from tool hire shop you will cut a neat hole and do a really nice job if your good at that sort of thing

Answer 9

Buying the doors first would be a very good idea and then simply measure the right size, I personally would get someone to fit them which should be cheap enough.

Answer 10

Wickes do a good quality range of double glazed french doors: http://www.wickes.co.uk/icat/pdextfrenchdr

They do hardwood and UPVC - I'd go with whatever you have in the rest of the house.

Unless you are FENSA registered, you are going to have to get building regulations approval for the change so you might be as well getting somebody FENSA registered to do it for you. You can read more here: http://www.planningportal.gov.uk/england/genpub/en/1115313928822.html