Basement hatch

Yes, joists only support the floor. Unless there's a wall on it...

But any structural wall would continue down through the floor and have supporting founds of its own. So the only other walls that would be built on a suspended floor would be lightweight 'stud' walls.

Essentially, you are right - it's chust the floor you need to worry about.

Yes, you can remove that adjacent joist, and take a bearer at right-angles over to the next joist so it carries the load instead. But, obviously, that next joist will now effectively be carrying 'double' the load, so it needs to be up to it.

Possibly, since it's close to a wall - so not the area subjected to the max bending forces - you will 'get away' with it, and all will be well. More likely is that you could could notice a bit of extra 'springiness' in the floor along that joist line, so you may need to 'double' that adjacent joist instead.

So, to sum up, I don't know what I'm talking about.

I just like talking.

No-one listens to me at home.

 

Is it damp in there, if so won't be good to store paper articles. Handy bit of room though, or a secret den.

 

Yes you can make the opening bigger very easily, you just need to fit double trimmers across to pick up the existing joist, you could also make the opening half way between the joists so it not a massive opening.

just hang the trimmers off of joist hangers of a suitable size.

 

Hmm, a bit overkill and underkill but would work ish.

 

You really want middlekill.

Yeah, I don't know what that means either.

 

It was late when I wrote that and I couldn't be bothered to explain that there was no point doubling up the trimmers if you didn't double up the joist they were being fastened to. The fact is that they didn't need doubling up in the first place.

 

Explain?? A double trimmer is standard practise and isn't for strength in the trimmer, but a more substantial fixing point for the joist that is now in free air as opposed to a solid point against a wall or a wall plate, much the same as if it was a loft hatch or a skylight window.

 

Look at the picture and then tell me that all those trimmers need doubling.

 

The originals don't but they are not picking up any joists, they are just forming an opening, having said that they are bigger timbers than the joist.

Just going on what I've always had to done to form an opening in any form of structure involving trimmers/headers.

 

You probably won't need the trimmers. Or, to put it another way, you'll probably 'get away' with it...

(But, Phil is obviously showing you the right way...)

It ain't going to collapse anyways. The worst that'll happen is that your floor will be a bit more springy. If it is, then you'll chust need to add the trimmers.

Obviously the ideal way is to inset the trimmer joist ends into the wall, but - tbh - chust bolting one alongside the existing will increase the joist's stiffness a goodly amount.

This is all a wee bit 'cowboy', of course, but will almost certainly be ok.

You are fortunate in that the hatch is close to the end of the joists, so relatively little 'bending' force/movement.

And, if it ain't all ok afterwards, it'll be obvious in chust some extra floor movement. In which case you know what you'll need to do...

 

I know what you mean Phil but in this situation the only trimmer that might have needed doubling was the left hand one as shown and the top joist which they are attaching to, as it happens with the short spans involved none of them need doubling. What I am calling trimmers are 1st and 2nd headers in your drawing.

 

Och it's chust the way it is.

Other end supported chu... er, just a metre away? You should have no probs.

 

Yeah, I did a double take there too. I always thought the 'trimmers' were the added 'cross'-bits.