Joist repairs

[ladylola]

In the past few weeks or so there have been a couple of questions about repairing of floor joists so I thought I'd post some pictures of a recent job of mine.
The building was showing some signs that something was amiss as can be seen on the ceiling

The boards were lifted to reveal
this masterpiece of engineering

A close up of a "repair" in the centre of a span approximately 7 feet wide, the ends are supported

The rest of the area was just as good

The softwood strips were removed and replaced in turn with bolted stainless plates

http://i729.photobucket.com/albums/ww298/photoluddite/_IGP5535.jpg[/img]
adding in extra oak packing pieces where necessary

All the plates in place

and finally boards back down and noone is any the wiser and the dainty folk of Brum can dance on there again

Of course this was a listed building which is why we went down that course and probably not very relevant to most posters querys but I though I'd share anyway.

 

[cardiy]

Where did you buy the metal brackets.

 

[gregers]

was there a supporting wall thats been removed at some point???

those floorboards are all over the place.

good repair though,did you jack the floor up a bit before fitting them?

 

[mattchip]

Good job!

 

[ladylola]

Cardiy I'll get back to you on that one can't remember off the top of my head.
Gregers, no there's never been a wall underneath. The building dates back to the late fifteenth century and that part was originally a malting floor as part of a brewery and pub. The original beams are mostly still in place and devide the room below into six "panels". At some point in the 1800's the floor was cut to accomidate a flight of stairs and some time after the stairs were removed and the repair was undertook. More work was done in the sixties when some of the boards were replaced. If you notice the boards closer to the window aren't the original oak but are iroko or something like.
We didn't jack the floor up but screwed a tempoary timber to the top and a gentle prop below, the timber is visable in one of the shots. The cracking has been caused more by the flexing of the joints than any sagging. It probably hasn't helped that the room has been used for weddings and parties. Then plates were fitted and the rest is history. The boards were however screwed down to facilitate future examinations to take place.
Mattchip, thanks for the comment.

 

[Static]

You really should have staggered the bolts.. but i guess anything is an improvement on the existing

 

[gregers]

i remember back in the early 90's a product we started to use was 4 plates that went round the joist you needed to repair each plate iirc had about 50 holes in it,that needed nails in all holes,so rather then removing the complete joist you could remove a section of it,say if the end was rotten,and they guaranteed up to a 1/3 of the span.iirc they were bat products,or my memory is playing tricks.

 

[ladylola]

Cardiy as promised the details of where we got the plates made. MODS please note I have NO affliation with this company http://iandtprojects.co.uk/
Bolts were simply stainless allthread which is availalbe off the shelf, I thoink screwfix do it.
Probably too far from you anyway but most small engineering workshops could provide the plates you may require.
Static I understand what you mean. There was a structural engineer involved with this so we work to his specs. To be fair the holes couldn't have been put much lower because of the difficulty of physically getting a drill in, taking down the ceiling wasn't an option and the positioning of the holes higher was discounted so we were left with the holes centerally. I do think, however, that the plates could have been longer, it may be seen in the one photo that the bolts are quite to the joint in the timbers. But as you say it's better than nothing.
Gregers I didn't use the system you refer to although I think I may have seen it in a catalouge. We've used all types of ways from plates to proper splices to glass rod reenforced resins. The strange thing is nowadays absolutely everything is stainless so that it will last but the timbers themselves are no longer treated to preserve them

 

[cardiy]

Cheers