New loft joists

[marsaday]

I have a few questions about joists and how to hang them in a loft conversion.

I have established which way i can hang the joists now and so there will be 2 spans in the area - 3.1m and 3.25m. I will be using the party wall and gable wall to hang off and then using the central spine wall.

i have been told 8 x2 joists will be fine (even though it looks like 6's would be fine).

Anyway i plan on bolting joists to the party and gable walls. i will hang joists off these with joist hangers.

1) is this the best way to go?

2) How do i actually bolt the joists to the walls? by this i mean how do i complete this task? is it a case of doing one bolt one and and then another bolt at the other and then drilling right through for the rest?

3) do the bolts go 4" into the wall and 2" through the joist. So needing 6" bolts or will 7" be better. The walls are solid 2 course of brick.

4) can you buy double joist hangers for where you bolt 2 joist together?

thanks

 

[marsaday]

i just remembered watching tommy walsh building a deck over a stream.

This deck was the entrance into the home and it had a stream running below. he did what i hope to do and used bolts. the only difference was that he used a glue squeezed into the bolt hole. i am sure this would be a good option.

anyone done such a thing?

 

[Framer]

they would be resin anchors


i dont mean to put a downer on your project but i realy dont think this kind of thing is a diy project, if you were just resting them on wall then perhaps not so bad but getting involved with bolting and hangers requires a bit of experience

if you were to do something wrong it could be fatal or at the very least cause a serious amount of damage to your house

would you do your own electrics, fit a gas supply or fix the brakes on your car?

pay a professional while you are out earning doing what you do

 

[Framer]

there is a website dedicated to deck failures which commonly use bolt on ledgers

http://www.deckfailure.com/index.html

 

[lostinfens]

Cant you cut into & rest your beams to the party/gable wall. Failing that is steel an option? On another forum I just mentioned a box girder made of timber & ply spanning from party to gable in your case then joists hung from that.
If you have a decent central wall then you're half way there.
There are a few options, what age is your property, is the party/gable wall in brick - 9" etc.
Don't be put off, if you approach it in a sensible way you'll be ok.

 

[marsaday]

i am up to the task no problem. i will have BC watching over me and a SE.

i will need some help and so will get a joiner to work with me for the floor.

Sitting on the spine wall i have a 9x2 joist which forms part of the kingbeam holding up the roof. All we do here is create a flitch beam using a channel steel bolted both sides. this way we get our main beam dividing the house.

i then run the joists off this and into the party and gable walls.

i think i know what i can do now in relation to the wall plate joists. Chemical anchors will be the way to go it seems.

 

[ollieman]

Let your engineer do the thinking. I'm converting my loft right now and I'm using Gluman beams to redude the span of the floor joists. The floor joits which are 6x2 will have a max span of around 2.9m, some of them need to be doubled etc. The Glulam beams I'm using sit on the central wall and on padstones embeded in the Party walls between me and the neighbour. The floor joists will be hung from the glulams thus strengthening the floor. Your engineer will not want you to bolt a supporting beam onto a wall, it'll most likely be supported directly off of a concrete padstone.


Cheers.

 

[jeds]

If the wall is aerated blocks I would use a standard HD joist hanger set into the wall. It's fairly easy to drill a slot for the hanger you then fix it in place with an injected resin grout.

If it's medium density block I would fix a timber wall plate to the wall with standard resin anchors at 600c/s and then hang the new joists from that with standard joist hangers.

Double and triple joist hangers are readily available.

 

[marsaday]

thanks all. engineer has nearly done his stuff and the central truss which will be converted into a steel is the main thing sorted.

as to hanging off the gable and party walls, i will just use a joist as a wall plate.

the walls are solid brick.

 

[ajrobb]

I have been looking at a renovation project and had a chat with my Local Council Building Inspector. If you are hanging stuff off party walls, you need WRITTEN permission from your neighbours to do the work. See the Party Wall etc Act 1996 planning portal at http://www.planningportal.gov.uk/england/public/buildingregs/legislation/bregspartywallact/

You might need a Structural Surveyor's report to state the work is safe. Your BE might provide this. It probably comes under his indemnity insurance, so expect to pay.

If you or your neighbours ever want to sell your properties, you might need the building work to the party walls carried out by an insured professional.

 

[geraldthehamster]

I have been looking at a renovation project and had a chat with my Local Council Building Inspector. If you are hanging stuff off party walls, you need WRITTEN permission from your neighbours to do the work. See the Party Wall etc Act 1996 planning portal at http://www.planningportal.gov.uk/england/public/buildingregs/legislation/bregspartywallact/

You might need a Structural Surveyor's report to state the work is safe. Your BE might provide this. It probably comes under his indemnity insurance, so expect to pay.

If you or your neighbours ever want to sell your properties, you might need the building work to the party walls carried out by an insured professional.

It's not written permission as such, but if you're fixing this to the party wall you do have to serve them a notice under the Party Wall Act. They can't stop you doing the work, but if they *don't* agree in writing you'll have to appoint a surveyor to write a report on how the work must be done - then you can do it. The Act is there to enable you to do the work - not to prevent it.

Re: the earlier comment about Tommy Walsh's desking, the bolts were fixed not with glue but with resin.

Cheers
Richard

 

[ajrobb]

It's not written permission as such, but if you're fixing this to the party wall you do have to serve them a notice under the Party Wall Act. They can't stop you doing the work, but if they *don't* agree in writing you'll have to appoint a surveyor to write a report on how the work must be done - then you can do it. The Act is there to enable you to do the work - not to prevent it.

Sorry, I thought a signed letter agreeing to the work was written permission. That is the best/cheapest way forward. As their neighbours seem to be agreeing verbally, I assumed they would sign the letter too, so I didn't mention the 'dispute' side.

As you say though, you could get up to 3 surveyors involved if the neighbours don't agree in writing within 2 weeks. Yes, if 2 surveyors agree the work is safe, they can't stop you forever. On the other hand, if the surveyors say the work is unsafe then you have to think again.

 

[marsaday]

hopefully be ok. i have to write to them first.

 

[geraldthehamster]

It's not written permission as such, but if you're fixing this to the party wall you do have to serve them a notice under the Party Wall Act. They can't stop you doing the work, but if they *don't* agree in writing you'll have to appoint a surveyor to write a report on how the work must be done - then you can do it. The Act is there to enable you to do the work - not to prevent it.

Sorry, I thought a signed letter agreeing to the work was written permission. That is the best/cheapest way forward. As their neighbours seem to be agreeing verbally, I assumed they would sign the letter too, so I didn't mention the 'dispute' side.

As you say though, you could get up to 3 surveyors involved if the neighbours don't agree in writing within 2 weeks. Yes, if 2 surveyors agree the work is safe, they can't stop you forever. On the other hand, if the surveyors say the work is unsafe then you have to think again.

Yes, you're quite right - I just wanted to avoid the impression that the neighbours' consent was needed. The worst that can happen if they don't respond favourably to the notice is a few weeks' delay and a lot of money out of your pocket to at least one surveyor (this happened to me over my loft conversion at a former property - steel into party wall - and cost me 900 quid for one surveyor and a structural engineer...)

Cheers
Richard

 

[ajrobb]

hopefully be ok. i have to write to them first.

Talk to them and say that you are going to submit a written notification and need them to sign an acceptance letter. I'd have a copy of the explanatory booklet already printed out to leave with them if they want. I'd suggest agreeing the scope of work (perhaps showing the engineer's drawings) and limitations (e.g. reasonable hours they need peace and quiet) before filling in the example letters. Then take the letters round for them to read and sign there and then.

Speaking for myself (lazy sod), I might not get round to signing within 2 weeks unless my neighbour was sitting with me. That would be a shame.