You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
I want to remove a chimney breast from two floors, this is the first floor, I've got to the point where the floor joists sit into the the chimney breast on the lower floor (neither Building Control, or the Structural Engineer Building control requested visits before I started work stated this would be the construction methodology or an issue!)
I'm completely new to this, but thought as ever, it'd just be a case of breaking down what's already there and making good what was left once the outer face was gone.
The two joists at the far end are tied into the brickwork of the wall - where the wall section shows only one run of bricks will need to be bricked back up to make a double skin as on the walls either side
Is it just a matter of chipping out the brick in the right area to bolt on new joist extensions and cement into the brickwork?
the one other problem I have is on one of the joists, I need to take the chimney down further before building the second row of bricks up for that to sit on...skyhooks on that one?
I'll discuss with Building control on Monday but some tips would be useful to gauge what's involved
Main reason for the removal is the kitchen worktops below back onto the chimney, the worktops are ancient / modded 500mm wide, not std 600, they but right up to a door at one end of the kitchen so it was either move the door out, get used to shimmy'ing around corners, or remove the chimney which makes the kitchen a good 40cm wider overall
Might be a daft question, has the chimney been removed from the roof or what's holding it if you remove the chimney breast?
Yeah the stacks gone, it was already removed when I moved in, if it was there to start with I'd have probably not taken this on
Assuming the roof chimney is gone?
Then its a case of extending the joists, this can be easy or difficult depending on the Building Control person.
Sensible approach is to extend the joist.... new bit of joist (fire treated) bolted to the original joist with coach bolts - suggest bit you bolt on is at least 4 x the gap you are bridging + the extra bit to go into the chopped out brickwork.
God knows with Building Control you could need , calculations, steels new joists **** knows.
What's the span of the joists in total across the room?
Not that I'm that familiar with this, but I think I'd want full new joists rather than extending/joining them.
tbf both guys who gave the go ahead where really good, just didn't say it might be a problem, I'll give them a call Monday for a revisit, just wanted to do things properly.
OK, I can get joists quick and easy from a wood yard in town, bolstering that brick out should just be a bit of time, level it up and bolt on a decent length of joist to the existing before removing the lower section, I can manage that I reckon.
It's about 2.8, probably 3m for the full joists with them bricked in either end
Actually....its going to be the main bathroom, I was thinking about putting a freestanding bath in there! hmmmmm.
To not quite answer your question but maybe provide some helpful info…
I replaced a couple of floor joists sorting out some damp issues. It wasn’t that bad, the most time consuming part was getting enough floor boards up to get at them properly (I tried to lift as few as possible but in hindsight just pulling lots up to get a bit more room to work would’ve helped a lot). It’s a bit of a faff manoeuvring a length of wood slightly longer than a room is wide into place, for obvious reasons.
So if you can easily pull the whole floor up, and depending what’s attached to/through the joists in question and how, consider just replacing them rather than faffing with extending.
Thanks, the wood slightly longer than the room scenario did cross my mind!
I'm not precious over the boards as 12mm chipboard or tile back board will be going straight over the top with tiles to finish,
Was more concerned that this is a distant way from my usual painting and decorating level of DIY and potential starting to effect structural integrity if botched.
Thanks, the wood slightly longer than the room scenario did cross my mind!
You just need to remember you need to be able to slide it in at an angle above then lower it down, or to the side.
The structural integrity thing was why I did the whole joists, I didn’t want to be having to fix it again! Whole new joist you can rest a lot happier than if it’s jointed somewhere (even though I’m sure there are good ways to do it).
Knock a hole in external wall and slide joist right through , or put a bridle in and joist off the bridle …
I certainly would not be thinking of replacing the entire joists - they are only supporting the floor. I have half a dozen joists that had the ends rotted out and were replaced with new ends - around 1m long on a 4.5 m span. these also support the weight of a stud wall and a dormer window. Its fine if done properly
Scarf joint? I'll caveat...IANA builder or chippy! However I know a scarf joint is how chippys make joists longer than available timbers. Robin the skill builder chippy makes it look easy on YouTube. TBF if I scarfed it I'd plate or both sides too.
Skyhook? I don't follow the problem but acroprop?
I would also plate a scarf joint....
Hangers would be easier than chipping the brick out but tbh some of these bricks fell away of their own accord when removing, they ain't the sturdiest, I'd feel safer with the extension slotted in and a bit of mortar used on the bricks around just for a bit of extra safety.
Reason for the skyhook is on all but one there's a second row for the brick to be cut away and the joist extended on to, where as the second from right has no second course, so I'll need to build that back up from the bottom before there's a ledge for it to sit on - I was thinking once the two either side are attached to the wall I'd just brace it for the time being until I've built the below up, there's only me here and I'll know not to go jumping around on it
Ahhh I getcha, the Joist that lines up with the flue from the ground floor...so only auntie skin of brick.... And you don't want to rip the kitchen out to brick they up before you finish this floor. Yes just brace for now. Hanger on the sides of the joists either side, brace joist between them and hanger on that.
I know you said the chimney had gone from the roof but has the it been removed from the roofspace also?
I think you would regret replacing the entire joist and no need. I would be doing as oldmanmtb says, extend with 4x length of gap and lots of coach bolts.
I’d think about plating it too with a L shape steel to support side and underneath. Although plate would be a bit OTT.
When I had out professionally done, the joist extensions were merely bolted alongside the old joist. They did create a pocket in brick for the end, but they also used a bracket below to support.
Hmm. I’m maybe over cautious but have you considered the structural impact of this? Have other houses on the road taken them out? I’m sure its possible but it might need so calf’s to back it up?
Thanks all, not as bad as I'd initially anticipated cost wise, bar potential for calc's needed so may need to factor in a structural report, i'll give building control a call in the morning hoping he agree's with the extensions, then it's just the time to core out the slots needed, the joisting and bolting I can do.
But to answer a couple of questions above, yes, all chimney above this section has gone, above and below tile level. My initial thoughts about the structural impact is why I've involved an engineer and BC previously, I did wonder what structural support, if any the chimney breast gave to the wall itself so I'm happy that full permissions we're agreed.
Acro props with a scaffolding board to spread the load. Make sure the acrows are on something solid. If they are on a first floor put another set of across below to transfer load alway to a solid floor. Lift some boards if a suspened ground floor.
Scarf joint are not made for Laos bearing wrt joist extending. A good lap or sandwich. Try to have bolts alternating. Make sure you overlap a good m or so.
That would be my plan anyway.
If you intend on joining a board to give you the desired length, its not just a matter of a few coach bolts, you'll also need jointing plates.
These are double sided spikey things that grip the two boards and make it far more sturdy. The bolt goes through them.the plate is sandwiched in between.
https://www.screwfix.com/p/sabrefix-m12-timber-connector-galvanised-dx275-50mm-x-50mm-50-pack/99094
If you intend on joining a board to give you the desired length, its not just a matter of a few coach bolts, you’ll also need jointing plates.
This. Otherwise the bolts will move in the holes and the joint will sag.
Thanks Dyna - will grab some once I have the approval!
Does M12's sound about right for bolts?
Other question I had is are the joists rated to C16 / C24 etc? or is that only for roof spaces?
the woodyard gave quotes on two lengths but I didnt ask about type as such
We had 2 rotten joist ends in an old house. Cut ends off, sandwich with two new lengths using coach bolts and spiked plates. This was to support a bath.
Hardest bit was getting access to drill the holes as my drill wouldn't fit in the gap.
Acro prop underneath whilst working.
Hardest bit was getting access to drill the holes as my drill wouldn’t fit in the gap.
This is my fear too, I've not tried for fit yet!
Now I'm stuck! As the gap across is 2m+ I've been asked to replace every other joist with new,
both ends are slotted into the brickwork, is there any way they can be slotted back in?
Or is it slot in one side and use a bracket for the other?
tbh I'm not unhappy I've uncovered this as some of the joists are completely shot, with a couple of botched jobs on the other ends where the previous owners cut and supported with about a foot of wood nailed to the existing!
If you are relaying the floor number up the boards and take a photo of them before you lift it
you can get dpc boots to go around the end of the joists if you haven't already considered them
Yeah I'll wrap the end in DPC, the boots dont appear to be readily available locally, tbh I'll probably put new boards on as the old ones are battered
both ends are slotted into the brickwork, is there any way they can be slotted back in?
A double depth socket at one end?
This is my fear too, I’ve not tried for fit yet!
Stub augers.
Designed for drilling between joists. You can buy sets or singles.
Also, if the gap is narrow you can use a right angled attachment for the drill. Its fiddly in use, but a bit of care taken shouldnt tax you too much.
Some have a chuck, others a hex fitting, so if buying one with a hex fitting make sure your stub augers are also hex fitting 😉
Dewalt version, but there are others.
'Tools-Scotland
After a bit of time I've got to this stage, I need to lay down the new bathroom flooring
I have half the old 25mm floorboards and would need to get the remainder planned from 32mm at cost, or re-do the whole with 21mm.
I'm tiling on top so could I just put moisture resistant chipboard onto the joists with tile backer board on top, or use 12mm plyboard instead + tile backer instead of the chipboard?
Joist centers are 16" apart from the first which weirdly was wider but I've put some noggins in to help strengthen
Watch and not fall through the joists and noggins look better staggered
Hardest bit was getting access to drill the holes as my drill wouldn’t fit in the gap.
Right angle drill!
You can get super stubby drill bits as well if it's really tight.
[url= https://live.staticflickr.com/5586/14919142125_605ffe1e08.jp g" target="_blank">https://live.staticflickr.com/5586/14919142125_605ffe1e08.jp g"/> [/img][/url][url= https://flic.kr/p/oJmvbn ]Makita Angle Drill[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
Fix the 25mm boards to the joists with 7mm spacers and use 32mm for the rest. Or add 4mm spacers to 21mm boards. If they're still not dead level, use playing cards as shims.
Could I not just go straight on top of the joists with 12mm ply then backing boards? It'd work out not far off the same as replacing half the floor boards I need
is there enough of one sort of floor to do the whole thing except whats under the bath? If its a fitted (vs freestanding) bath the floor doesnt need to be t he same level underneath it