Increasing the size of the loft hatch

thecrater · Post by **thecrater** » Tue Jun 20, 2023 11:09 am

Hello
My loft hatch is currently a push up 600mm x 600mm hatch.

I am considering changing this to a hatch with a built-in ladder to allow easy access to the loft space.

I thought I would seek advice from the forum as regards the following:

Are there any building regulations that I should be aware of?
Looking at the pictures, does the plan look feasible?

: View from loft; Image00004.jpg (174.99 KiB) Viewed 2795 times

View from the loft.

: View from bottom; Image00003.jpg (141.85 KiB) Viewed 2795 times

View from the corridor. Showing plan to extend.

: Current hatch installation; Image00002.jpg (175.95 KiB) Viewed 2795 times

How the current hatch is installed.

: Joists; Image00001.jpg (207.74 KiB) Viewed 2795 times

Joists connected near where the new hatch will be. Is this likely to cause issues?

Bob225 · Post by **Bob225** » Tue Jun 20, 2023 1:31 pm

i would sister where that joint is, and double up the noggins/headers

https://access-panel.com/Loft-Hatch?page=2

is 600 mm wide enough

thecrater · Post by **thecrater** » Tue Jun 20, 2023 10:17 pm

Thanks @Bob225

I will take that into account.

As regards the width, The space between the joists is 600mm and I would rather not take any risks. What's the size of a typical hatch? I've seen a few that are 600mm x 1200mm.

Gadget · Post by **Gadget** » Tue Jun 20, 2023 11:01 pm

thecrater wrote: ↑Tue Jun 20, 2023 10:17 pm Thanks @Bob225

I will take that into account.

As regards the width, The space between the joists is 600mm and I would rather not take any risks. What's the size of a typical hatch? I've seen a few that are 600mm x 1200mm.

A hatch can be made any size you want within reason, as long as it's made properly and safely.

big-all · Post by **big-all** » Tue Jun 20, 2023 11:13 pm

has the third picture down called "joists" been digitally altered in any way from the connection plate the top surface carries on out off sight in a strait line the wood grain on the face both does the same but the solid does a right angle so not a real picture ??

ok looks like it may just be strong shadows further confused by lots off reflection :dunno:

Argyll · Post by **Argyll** » Wed Jun 21, 2023 8:43 am

I'd also use joist hangers for the new noggins. In the old days they just used nails which is probably what you have and joist hangers weren't a thing. Joist hangers are so much better.

thecrater · Post by **thecrater** » Wed Jun 21, 2023 11:43 am

Argyll wrote: ↑Wed Jun 21, 2023 8:43 am I'd also use joist hangers for the new noggins. In the old days they just used nails which is probably what you have and joist hangers weren't a thing. Joist hangers are so much better.

No. The picture has not been modified at all. If you look at the top picture entitled "view from loft", the joist us the one at the bottom left hand side near the theoretical location of the noggin. If you zoom in you'll see the metal piece connecting the joists.

thecrater · Post by **thecrater** » Wed Jun 21, 2023 11:46 am

I was thinking of extending g the exidtjng hatch by another 300mm to make it 600mm x 900mm. Would this be good enough for a hach with a built-in ladder? I don't want to spend a lot of money on it. Just a working and safe way to get to the loft space.

Argyll · Post by **Argyll** » Thu Jun 22, 2023 3:03 pm

thecrater wrote: ↑Wed Jun 21, 2023 11:43 am
Argyll wrote: ↑Wed Jun 21, 2023 8:43 am I'd also use joist hangers for the new noggins. In the old days they just used nails which is probably what you have and joist hangers weren't a thing. Joist hangers are so much better.
No. The picture has not been modified at all. If you look at the top picture entitled "view from loft", the joist us the one at the bottom left hand side near the theoretical location of the noggin. If you zoom in you'll see the metal piece connecting the joists.

Yeah, but thats not a joist hanger. Thats to connect the joists.

fin · Post by **fin** » Fri Jun 23, 2023 6:34 pm

if the ceiling joists pictured with the connector plate is a truss and what you propose means cutting through another one that is a really bad idea. trusses do not fail. but if you modify one then that might cause them to fail.

you can buy insulated loft hatches with a ladder built into it from a few manufacturers. fakro off top of my head is one.

theyre in the region of 600 by 1100 or 1200 but obviously they go between the trusses if that is the type of roof construction

fin · Post by **fin** » Fri Jun 23, 2023 6:36 pm

actually looking again yes you can move that timber. under no circumstances can you cut the others though. and dont remove the nail plate on the bottom chord of the truss either.

thecrater · Post by **thecrater** » Fri Jun 23, 2023 11:37 pm

fin wrote: ↑Fri Jun 23, 2023 6:36 pm actually looking again yes you can move that timber. under no circumstances can you cut the others though. and dont remove the nail plate on the bottom chord of the truss either.

The plan is to simply move that piece of timber far enough to be able to extend the existing hatch as per the pictures above to install the following loft access kit from Wikes.

https://www.wickes.co.uk/Youngman-Timbe ... t/p/183453

The dimensions are 550mm x 1130 mm

On the box it says minimum required width is 570 and my current width is 600. Would this be an issue? There's about 25mm gap either side, would this present a problem when installing the hatch?

Bob225 · Post by **Bob225** » Sat Jun 24, 2023 3:01 pm

You can't just move it, you need to put in the joists/noggins first and double each side up to take the loading - especially as you have a joint plates in there, if you don't strength them by sistering them you are asking for problems

as for the width, you can pack it out, but each end needs to be solid timber

fin · Post by **fin** » Sat Jun 24, 2023 6:27 pm

Bob225 wrote: ↑Sat Jun 24, 2023 3:01 pm You can't just move it, you need to put in the joists/noggins first and double each side up to take the loading - especially as you have a joint plates in there, if you don't strength them by sistering them you are asking for problems

as for the width, you can pack it out, but each end needs to be solid timber

how i understand it is that the roof structure is truss rafters. obviously we need the op to confirm this.

those plates look to me to be the bottom chord of a truss.

so long as that is not cut at all or altered then he is ok.

that nog can just be moved backwards.

if its a truss rafter then that is taking all the load. that nog is litterally there to create the opening.

fin · Post by **fin** » Sat Jun 24, 2023 6:29 pm

thecrater wrote: ↑Fri Jun 23, 2023 11:37 pm
fin wrote: ↑Fri Jun 23, 2023 6:36 pm actually looking again yes you can move that timber. under no circumstances can you cut the others though. and dont remove the nail plate on the bottom chord of the truss either.
The plan is to simply move that piece of timber far enough to be able to extend the existing hatch as per the pictures above to install the following loft access kit from Wikes.

<a href="https://www.wickes.co.uk/Youngman-Timbe ... t/p/183453" class="skimlinks-unlinked" data-skimwords-word="https%3A%2F%2Fwww.wickes.co.uk%2FYoungman-Timberline-Loft-Ladder-Access-Kit%2Fp%2F183453" data-skim-creative="500005" title="">https://www.wickes.co.uk/Youngman-Timbe ... /183453</a>

The dimensions are 550mm x 1130 mm

On the box it says minimum required width is 570 and my current width is 600. Would this be an issue? There's about 25mm gap either side, would this present a problem when installing the hatch?

yes that should be fine. when i fit these i usually attach some extra timber to temporarily hold it in place after lifting it into the opening. probably worth while also attaching some timbers to the side youll see too. on the parts that will be hidden by architrave obviously. then just timber wedges to adjust to suit. then screw it in place through the wedges. use some expanding foam to fill the gaps and then trim off with architrave. easy enough to do.