French Doors and Building Regulation

[pmlavers]

I am considering replacing a large sash window in the back of my house with Fench Doors onto a patio. I think I will need to fit a lintel as the house is a victorian one that seems to use wooden window frames as structural support. Apart from that I will not need to widen the opening, simply remove the 50cm or so of brickwork beneath the existing window.

I am after any advice or experience from others. Particularly with respect to any building regs I must meet. I am hoping to be able to fit doors with glass to the ground in small panes with window bars as light is at a premium in the room. Does it have to be a) toughend and b) double/triple glazed? Do I need to involve Building Control if I don't need to fit a lintel? Etc. Many Thanks

[Phil Anthropist]

I am having similar work done this week but the opening is such that there is not enough space to have two doors. There will be one single door and a narrow single fixed window next to that. The glass in the door and fixed single panel will be in single panels not separated by glazing bars. It will be double glazed and has to be toughened glass. I am not be having a new lintel fitted, and building control has not been involved. I don't know whether building control is involved if you need a new lintel.

[Christian McArdle]

Normally safety glass must be used. It must be used for all windows up to

800mm and all doors up to 1500mm. However, there is an exemption for "small panes". These must be genuine separate units, not just a big unit with stuck on bars. They must be no wider than 250mm and contain no more than 0.5m2 each. The glass must be at least 6mm thick. However, I would advise against using this exemption and use toughened glass anyway.

Yes, with low emissivity (i.e. Pilkington K) glass. although you might be able to find some sort of exemption through the maze of building regulations.

You need to inform building control even without a lintel, unless you use a FENSA approved contractor. This is to ensure that the correct glazing has been used.

Christian.

[Phil Anthropist]

Triple glazed doors will be very heavy.

[dg]

I did not think that a FENSA contractor could certify the structural work ie fitting of a lintel and intalling DPC and insulating reveals? Only the window installation.

dg

[pmlavers]

Thanks. I guess the best way forward, as usual is to speak to my local BCO.

[Christian McArdle]

Indeed, I didn't mean to suggest otherwise.

Christian.

[jim2000]

If your're putting a lintel in then that should be notified to Building Control. Cannot be self-certified under FENSA as it's structural.

In general, the glazing needs to be toughened and the door must meet stringent insulation requirements ("U values") found in Approved Doc. Part L. If you want timber (as opposed to PVCu) french doors this will be very expensive, and will in any case involve double glazed units with big air gaps.

You can get around the Part L insulation requirements by using a door having less that 50% of its area (inc. the frame) glazed, which would then be exempt. This can easily be achieved with french doors that have short solid panels at the bottom.

[The Natural Philosopher]

I think - 2000 regs anyway - that 4mm is the minimum for small panes..and it proved impossible to find a company that would toughen panes that small, as it happened, for me.

[Christian McArdle]

They now say 6mm for annealed glass, or 4mm for leaded/coppered. Obviously, safety can be any thickness.

Christian.

[Chris Bacon]

What does "all windows up to 800mm" mean?

AFAIK 4mm is OK - why use toughened glass in small panes anyway? The exemption is there for a reason.

[Christian McArdle]

It means any window pane, part of which is within 800mm of the finished floor level. Proximity to a door may also count, too.

Possibly because one such small untoughened pane within a door went right through my wrist, partially severing 2 tendons and completely severing the median nerve.

Christian.

[The Natural Philosopher]

I could not FIND toughened at the pane size I wanted..leaded lights. I would have been happy to reglaze with it if I could.

Leaded lights are a bit kinder than panel on wood/metal framed glazing..the class tends to fall out of the lead when broken, rather than leaving stiff sharp shards.

How did you come to have this happen? It sounds like a story worth retelling for safety reasons..

[Chris Bacon]

How the hell did you do that?

[Christian McArdle]

You might find it easier to find laminated safety glass in small sizes, as it can be cut after manufacture.

Door kicked open with excessive force by my brother. My hand was reaching for the door handle. Glass panel made contact with hand. Door pushed arm back until elbow hit the wall (which was adjacent and at right angles to the wall containing the door) and arm was wedged between wall and glass panel. Door did not stop moving, causing glass the break. Very long shards have a good rumage around inside wrist.

Christian.

[Stuart Noble]

I remember a similar instance next door, also caused by a sibling at the sort of age when the front door is used to express your feelings

[Guy King]

The message from Stuart Noble contains these words:

I remember a friend shoving his sister's head through the wall of their greatly extended pre-fab.

[The Natural Philosopher]

I bet she deserved it to. I smashed a window to get back in when MY sister locked me out. She had some explaining to do...

[meow2222]

snip

would this be your late brother by any chance?

NT

[meow2222]

I get the feeling you dont actually know what the struc support situation is there? Vic houses normally use a brick arch to do the support. Of course there are exceptions as you say, such as structurally supporting window frames, hidden steel support strips, and not unusual to find no brickwork support.

Laminated glass is good for small panes. Its safe but not as strong as toughened, and its more work for burglars to get through.

NT