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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Joists buckling https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1538597913 Message started by Lou789 on Oct 3^rd, 2018, 9:18pm

Title: Joists buckling
Post by Lou789 on Oct 3^rd, 2018, 9:18pm

Hi I have just had a loft conversion completed and noticed one of the door frames and/or the ceiling is not straight. The builder tells me this is because the joist has bowed & has said he can't odds it with such long lengths there were bound to be a few out.

Is this correct ? I would be grateful for any advice

many thanks

Title: Re: Joists buckling
Post by woodsmith on Oct 4^th, 2018, 9:04am

It's difficult to say for sure without seeing the extent of the problem but if your builder has fitted long (over 2.4m) joists without fitting herringbone struts, often called noggins, that could cause the floor and ceiling to distort.

Title: Re: Joists buckling
Post by big_all on Oct 4^th, 2018, 11:59am

as you dont fit doors and frames until the structure is fully loaded even allowing for deflection with the load i would expect the doors fit correctly ideally with a 2mm/2p coin gap all round but no more than 3mm
what gaps do you have and where

Title: Re: Joists buckling
Post by CWatters on Oct 4^th, 2018, 3:48pm

Quote:

Hi I have just had a loft conversion completed

Were Building Control involved?

Title: Re: Joists buckling
Post by CWatters on Oct 4^th, 2018, 3:50pm

Without seeing photos it's hard to say what the problem is but I would like to think that if I was doing a loft conversion I would have found a solution that didn't look wrong.

Title: Re: Joists buckling
Post by Lou789 on Oct 5^th, 2018, 2:04pm

Thank you for all your replies I am having trouble uploading a photo but am working on it !

[gallery fullsize]LouLou123/1538761007.jpeg[/gallery]

[edit]Photo attached to post.[/edit]

Title: Re: Joists buckling
Post by Lou789 on Oct 5^th, 2018, 7:26pm

Does the photo help it is hard to get a spirit level to check because of the height of the door frame and ceiling.

Title: Re: Joists buckling
Post by thescruff on Oct 5^th, 2018, 10:31pm

Looks like the ceiling has dropped over the hinge side, is that correct?

What are the size of the joists and the unsupported span?

Title: Re: Joists buckling
Post by Lou789 on Oct 5^th, 2018, 10:57pm

I don't know the size of the joists and will need to ask the builder.

The builder initially said the joist has bowed and then when he came and looked at it he says that the ceiling runs very slightly out.

To be honest I have lost a bit of confidence in them because of another issue but it has passed building regs but that chap was very easy going.

I thought it may be the frame.

If its the roof is that acceptable?

Title: Re: Joists buckling
Post by Lou789 on Oct 5^th, 2018, 11:17pm

[gallery fullsize]LouLou123/1538777698.jpg[/gallery]

I don't know if this helps - the frame on the right of the picture is the door frame in the previous picture

Title: Re: Joists buckling
Post by thescruff on Oct 5^th, 2018, 11:50pm

Can't see a lot of wood to hold the edge of the PB up.

did he board the ceiling or walls first.?

If he did the ceiling first have you the same pic showing it fixed.

Title: Re: Joists buckling
Post by Lou789 on Oct 6^th, 2018, 7:17am

Thank you. No these are the only ones I have. Sorry to be ignorant what is a PB?

I don't know if he did the ceiling or walls first.

Should I be concerned & if so should I pass this by the building regs chap?

It has not passed because I asked him not to do so about another small issue.

Title: Re: Joists buckling
Post by thescruff on Oct 6^th, 2018, 11:00am

PB-Plasterboard.

In the 2nd pic, the ceiling joist above the left side of the door is high, whereas the one to the right looks low and mostly hidden in the stud wall, making a good fixing for the ceiling suspect.

Timbers don't come or stay straight, I wouldn't worry about it.

If anything you could ask the builder to fit a wider architrave and scribe it to the ceiling to hide the uneven gap

Title: Re: Joists buckling
Post by londonman on Oct 6^th, 2018, 5:10pm

If the joists had dropped or buckled then you would see cracking in the paint on the architrave. The door would also not sit square in the door frame. However from the photos neither are obvious and so my take is that he got his levels a bit wrong with his studding.

TBH it looks quite a tidy job although as Scruff has mentioned, you would expect to see some timber support between those ceiling joists on either side of that stud wall (where the door is) for the ceiling plasterboard to pick up and screw to. Otherwise it will flex constantly at that joint and crack. It's quite possible that he fitted some after the photo was taken.

I wouldn't worry about it unless the 'other matter' that you refer to has an influence on what we're talking about.

The only slight negative criticism is that the gap around between the door and door frame is rather large TBH. Aesthetically looks wrong. I assume that he fitted door stops at a later date ?

Building Control aren't interested in levels (unless they are critically affecting the structure) or plasterboard for that matter.

Title: Re: Joists buckling
Post by CWatters on Oct 6^th, 2018, 6:09pm

thescruff wrote on Oct 5^th, 2018, 11:50pm:

Can't see a lot of wood to hold the edge of the PB up.

That looks like the cause to me. Perhaps they didn't fit a batten to the side of the joist so that corner of the board has sagged. Perhaps they did but it wasn't level.

Title: Re: Joists buckling
Post by Lectrician on Oct 7^th, 2018, 7:53am

Which door frame in the second photo? Is it the one to the right through the first frame?

If so, it looks like the flat roof (I assume flat roof?) has a fall on it as it should, although it’s usual to put the bottom of the beams in level, and add a strip to the top to introduce the fall.

Title: Re: Joists buckling
Post by thescruff on Oct 7^th, 2018, 8:57am

As a reminder to anyone having this type of work done, it's important to take lots of pics for later records and interest, so, get snapping people you can't take too many.