Cutting Trusses to install hatch?

gardnt1

Hi,
i have a trusrafter structure in loft and want to install a new loft ladder. Obvious question i have is that the only real site for this new ladder requires me to cut the tie (ceiling joist) for the trusses. question is, as long as i install a piece of timber bolted to the lenth of tie that i want to remove some from, would this be ok?

I have read that these structures should not be touched? but the loft ladder edge will be replavcing the removed bit and braced as mantioned with another timber........any advice appreciated asap!

thanks.

raymond

Roof structures MUST not be touched.

Unless you can safely calculate the loads on the old and new structures and install the correct gtade and size of timbers get a builder ..

paul_h

I would have to agree. The ceiling joist is an integral part of the strength of a trussed rafter and should not normally be cut. It's function is to prevent the roof support from splaying outwards, and is under considerable tension.

It is possible to tie the cut ceiling joists into the ones either side, but it requires careful consideration by a structural engineer, and building control consent.

Mr_Warren_2

Utter crap.....sorry boys but you go a bit far.....you can install a roof ladder without a structural engineer or building planning/regs and the job can be done in one single afternoon. DYI semi-expert level I agree but pel-lease don't frighten the poor gardnt1. He/she not talking about hacking his roof joist, just making an opening in his ceiling.

You can easily cut your ceiling joists and use the off cut (if big enough) to but end where the cut was and fix appropriately on the two adjoining joists/trusses whatever. Do the same at the other end and then cut your ceiling to match the opening. Make good the ugly gap by boxing with suitable planks (15mm should do). Any good DIY store have leaflets helping you do this job.

Nile

Users will have differing opinions from time to time but please remember to be nice to other MoneySavers.

Mr_Warren_2

Frustration got the better of me ! I said sorry........

gardnt1

Have to admit that i have spoken to several structural engineers today........some said dont cut whatever..dont even notch for cables as a trusrafter roof is designed to use minimum timber and ceiling ties are the most integral part.........

the trusrafter association said i could cut, but i would need a structural engineer to do the maths as the adjoining truses could not simply be used to support the cut!

others said £400 quid!!

I have now decided , to fit elsewhere without cutting anything as it all seems so much hassle!

Thanks all!

raymond

Mr_Warren wrote:

Utter crap.....sorry boys but you go a bit far.....you can install a roof ladder without a structural engineer or building planning/regs and the job can be done in one single afternoon. DYI semi-expert level I agree but pel-lease don't frighten the poor gardnt1. He/she not talking about hacking his roof joist, just making an opening in his ceiling.

You can easily cut your ceiling joists and use the off cut (if big enough) to but end where the cut was and fix appropriately on the two adjoining joists/trusses whatever. Do the same at the other end and then cut your ceiling to match the opening. Make good the ugly gap by boxing with suitable planks (15mm should do). Any good DIY store have leaflets helping you do this job.

It is easy to do if you know what you are doing, but in reality the calculations NEED to be done. Most builders will get away with "overkill" where it is actually stronger than it needs to be just to be safe rather than do the sums, but that comes with experience and if someone needs to ask then they DONT have the experience required.

By the way, any loft ladders I have seen are designed to fit a standard opening and do not involve "hacking" joists.

paul_h

There's no need to be so rude Mr Warren just because my opinion differs from yours. Just say your bit, and the OP can make his own mind up, and/or take further advice as necessary.

Mr_Warren wrote:

He/she not talking about hacking his roof joist, just making an opening in his ceiling.

The OP was not talking about just making an opening, I believe he was talking about cutting ceiling joists to accomodate a non-standard opening.

gardnt1 wrote:

Obvious question i have is that the only real site for this new ladder requires me to cut the tie (ceiling joist) for the trusses.

That sounds like cutting ceiling joists to me. The OP could have been talking about a trimmer (between trusses), these can be moved - but TR ceiling joists should never be cut.

What you must understand is that the ceiling joist is as structurally integral to a trussed rafter as the roof rafter, as confirmed by the Structural Engineers he has subsequently contacted. Whilst it won't make his house fall down, non-standard loft openings which are not correctly executed will be picked up on future surveys if the OP ever wanted to sell.

http://www.tra.org.uk/pdf_files/pds7.pdf

gardnt1

Didnt realise this would cause so much discussion!

To be fair, i have experience in DIY quite extensively and have aquired many skills over the years, some of which i use daily. Some jobs , which I have never personally tackled I like to get advice.....quite sensibly. The last post hit the nail on the head. It appears that its only if I come to sell the house that all hell will break loose if I had cut into a TR without proper calulations....even if a 'builder' had over compensated with noggins here there and everywhere.

I have a standard 550mm wide ladder, joists are 575mm, however the way the joist run and the landing space the only place i could realistically fit had a stud wall in the way! I didnt want to fit in a bedroom.

I have solved the dilema and hatch is now sitting pretty in the area I wanted it to go.....I lost the thickness of one hatch side and incorparated the side of the ceiling joist as the 'new' side. This gave me the necessary clearance from the stud wall.........all is well! No TR's cut! Thanks all again.