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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Resin bolting hanagers to a wall... https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1271839394 Message started by CWatters on Apr 21^st, 2010, 9:43am

Title: Resin bolting hanagers to a wall...
Post by CWatters on Apr 21^st, 2010, 9:43am

Anyone care to comment on this post...

http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=5693&page=1

Quote:

He [an SE] wants me to use individual hangers resin bolted to the walls. So i am not using a joist as a wall plate. Everyone i have spoken to say this is a bit odd.

I'm happy to cross post replies.

Title: Re: Resin bolting hanagers to a wall...
Post by Joiner on Apr 21^st, 2010, 1:11pm

Not a lot of information on there CW, but from the description of the rafters/joists it sounds like an older building.

I'd ask for a description of the state of the brickwork, if only to firm-up my opinion, because it could explain the use of resin-fixed bolts. The only thing I'd question is why the SE has stipulated individual hangers instead of resin-fixing the bolts holding a wall plate along the party and gable walls and hanging the joists off that off joist hangers.

Just because the method's 'different' doesn't make it odd. But then it was posted on the GBF and they do have a tendency to turn things over and do a forensic inspection for hidden markings and then discuss the possibility of hidden consequences for the future existence of the human race.

Title: Re: Resin bolting hanagers to a wall...
Post by marsaday on Apr 23^rd, 2010, 10:36am

Hi, this is my problem from the other thread.

The house was built in 1910 and the brick work in the attic is a bit rough.

The SE (i think) has never done a loft conversion before and so is being ery careful. he says individual joist hangers as opposed to a wall plate gives a rolls royce job instead of a mondeo.

he is worried about "point loadings" apparently. you see on one wall there is a chimney breast we have to trim round and so there will be corners where the wall plate will be weak (at the edges i think). This is where he wants to double trim and so more loading will be on this point.

i will be doing the work and understand the wall plate way is much easier.

i wondered what chages there would be if i went over to a wall plate design?

i can give you more info if needed.

Title: Re: Resin bolting hanagers to a wall...
Post by Joiner on Apr 23^rd, 2010, 6:51pm

The SE sounds like a bit of a dickhead. God knows where he's coming from on this one.

Trimming around the chimney breast means you can fix the wall plate to the party wall/gable end (whichever wall the chimney breast is on AND around the chimney breast, fixing it together at the corners by either mitering, screwing through and reinforcing with brackets, or just fixing at the corners with brackets, putting fixings into the SIDES of the chimney breast as well. That isn't going to go anywhere!

The idea that individual joist hangers are somehow better than a (load-spreading) wall plate seems a tad eccentric, because you can resin-fix the wall plate bolts at the same centres and get a far superior location for the joist hangers.

What do you think Jerry?

Title: Re: Resin bolting hanagers to a wall...
Post by woodsmith on Apr 23^rd, 2010, 11:19pm

Individual hangers would be better if the wall has a bow :-/.

Title: Re: Resin bolting hanagers to a wall...
Post by Joiner on Apr 24^th, 2010, 8:47am

Trouble then is, the bow will put the joist hangers out of true.

I've fitted wall plates in stone barns where you'd be hard-pushed to find a straight line. We put the upper storeys in using 1/2" (it was that long ago) threaded rod epoxy'd into the masonry, and packing to give a tight fix. The nuts and washers were counter-bored flush and a 2" board (slotted to take the joists) glued and screwed (again, counter-bored and plugged) to the face. It was all oak so looked of a piece when done. The gaps where the first plate didn't meet the wall were just lime mortared to match the existing.

The reason for using epoxy is to avoid the pressure of something like a rawlbolt splitting the stone/brickwork. The pressure created by them is incredible. I'd made a new iron ladder to fit into the tower of Broncroft Castle (privately owned, it's down the Corvedale in Shropshire) and as I tightened the second rawlbolt a hairline crack appeared in the bloody great slab of sandstone. I backed that off pretty smartish.

Maybe the SE does see something no one can see, he is on site after all, so perhaps a closer questioning of his reasoning might be in order. If his only concern is getting around the chimney breast then he really shouldn't be doing this kind of work until he's got his knees a bit browner.

Title: Re: Resin bolting hanagers to a wall...
Post by marsaday on Apr 24^th, 2010, 10:06am

the BC officer is happy to use a wall plate and so this will be the way to go. It is pointless in questioning the SE as i can see he really doesnt know what he is doing. all theoretical and not practical.

He didnt even survey the area properly. had to come back again when questioned about something. so he hasnt seen the brick work which is not bowed.

i have another problem which i am asking him about at this moment. dont want to confuse him with this.

Anyway, could you tell me what i do when i come to the corner of the chimney breast. There are two stacks coming up into the attic and so this means i will have 3 sections of wall plate (left side, middle of both breasts, right side).

So to make the corners stronger i just add L brackets / straps to the wall plate and screw into the side of the breast? What screw method do i use. Only one stack is still used and that is an open fire.