Enlarging bathroom window

26 Aug 2013
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United Kingdom
A quick hello to all who reads & replies

We are after a bit of advice regarding a bathroom window that we'd like to enlarge or have enlarged.

Bathroom and toilet was separate till a few days ago- but now we are left with the small loo window that looks a bit ridiculous-

Unfortunately the existing lintel does not run continuous between both- so it would need replacing if we decide to go ahead with the enlargement.

Would this be a relative straight forward operation or best left as is?
Would we need a building control cert upon completion?
Rough pricing on having this done?

I'd imagine the upper course of bricks would need to be supported upon removal/replacement of a new lintel?

Kind regards
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I've searched the net for something similar diy but can't seem to find something similar to judge my competence level.

Am I up against something that would best be left to somebody in the know or is this in the scope of diy.

If I was looking to do it myself I'd rake/cut the mortar joints as far as possible. Slide in acrow props & remove both lintels.
Slide in new lintel into position & repoint brickwork/lintel from inside.
Remove brickwork on outside up to desired opening and then proceed to remove window.

What I am unsure about is if the inside/outside brickwork would be able to support itself while removing the lintels and window or would they need to be propped up for sure.

I'd be confident enough tackling the job myself, but just need to do a bit of homework before going in guns blazing.

If I was doing the job, I'd prop the roof and take the brickwork down over the lintels. It's only a 30min job to put it back on a catnic.
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That's another way of looking at it- thanks Stu.
Would benefit from removing the bricks above the lintel as I'd be using them to match the outside when blocking up the small window.
Catnic lintel would be much easier to handle & prolly half the weight as well.

Suppose the roof wouldn't even need that much support over a 2.5m stretch?

You need boards on ceiling and floor with acros. When I've done jobs like this with building firms they always propped below to solid ground.
Thanks for your reply Stuart-

Suppose it'll give easier access to the lintels having the roof supported from the outside- although that means 5m+ acrows.

Would I be able to support from the floor joists rather than from the outside?

I'll make sure to take pictures and post them here once ready to start cutting.

Prop from the inside. When I said solid ground, I meant the ground floor below was also propped under where the top was. Timber floors may bounce slightly, but I know people that have just propped the top floor for putting a window in.
You can keep the props back from the window a few feet for access.
Ahh right- now I get the picture.
The floor joists that I'll be supporting from runs parallel with the wall, so think it would be wise supporting the ceiling/joist from the bottom as well.

Thanks once again for your advice- much appreciated

Iv'e been speaking to a final year structural engineering student on what he would have done & he came up with something different.

I'm not entirely convinced by the idea- so asked him to run it by his tutor.

What he proposed is the following:
Remove small window and brick it up to lintel height and then remove brickwork between the 2 lintels. (unsupported section at this stage will be about 900mm)
Remove small lintel and drill 4 x 10mm holes into faces of both lintels.
Attach 4 x 8mm rebar starter bars into lintel with hilti hit chemical resin & wait to dry.
Slide smaller linten into position with chemfix sqiurted into holes.
Shutter the gap between the 2 lintels with ply & fill with concrete.

Like I said- not 100% convince with this yet, but cant see why it wont work

Any thoughts on this?

Always good to here another method, although it's probably not one I would have thought of.
Are you going through Building Control?
How big is the new window, and where will it line up on the outside?
Normally they line up with the windows below.
Hi there Stuart- thanks once again for your reply.

If we do decide to continue I'll have a chat to our local Bco and see if they need to issue a cert for the works carried out- already had him over to sign off the drainage that's been diverted and he seems like a nice enough chap.

I've had a look and the windows won't be lining up... so the chemfix/entension bar method won't work.
If it needs doing we might as well do it properly and get the two to line up.

Will have a chat to the missus tell her what needs doing.


Just had a quick measure & chat to the missus.
The lintel extension proposal will still work and the 2 windows (top and bottom will be lining up perfectly.

Guess the next step is to send the proposal in to the BCO to see if they'd be ok with the lintel extension.
I'll email Hilti Uk with the above and see if they recommend joining concrete lintels with before sending off the application (with the email attached)


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