Adding a bathroom - sistering joists, new water supply, new boiler + cylinder

Mason-

Mason-

Mason-

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Hi all,

I'll try to be explain as briefly as possible. We want to add a bathroom upstairs where there wasn't one before. As well as moving the hot water cylinder up there. I had a structural engineer round to work things out. If we just want the bathroom, no strengthening is required. If we want the bathroom and the cylinder, we need to double up 2 of the joists.

This is a rough overview of the bathroom:


The engineers request:


The joists that sit on the wall to the left is easy, the top of that wall can be completely exposed so I can just sit the joist on top and bolt it to the existing. The issue comes with the right hand side, this is the party wall with my neighbour. Of course I need a party wall agreement.

Here is a photo of the 2 joists where they are socketed into the wall:



Here is where I need some help. I see these options:
  1. Widen the pocket in the brickwork where the existing joists go to take both of the new joists. Messy but doable.
  2. Some sort of hanger that I can fix to masonry. This seems impossible? The only one I think could work is a double width timber to masonry hanger. But to get it around both of them I need access from below, which I really want to avoid.

Is there any other option? Fixing a rim joist/wall plate and using a timber to timber hanger I don't think will be acceptable because it can only be in the space between the 2 joists which surely is not enough.

I appreciate any advice, thanks.
 
Think I've found a suitable hanger :D

timco.co.uk

Welded Masonry Joist Hangers - A2 Stainless Steel

TIMCO is a supplier of essential products that trade professionals rely on every day. Over 7,000 quality products across all essential categories: Screws, Fasteners & Fixings, Nails, Adhesives & Building Chemicals, Powertool Accessories & Hand Tools, Building Hardware & Site Protection, Security...
timco.co.uk timco.co.uk

That makes life easier.
 
Random Q, why would they need to be connected to the existing joists rather than being in the middle of them and so just making the gaps smaller? Not sure if it makes a difference but that's why I'm no structural engineer!

Check load ratings on those things, not sure what the safety factor would be but they're approx 300kg each, share the load over the existing joists and it's probably fine?
 
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Rob_B said:
Random Q, why would they need to be connected to the existing joists rather than being in the middle of them and so just making the gaps smaller? Not sure if it makes a difference but that's why I'm no structural engineer!

Check load ratings on those things, not sure what the safety factor would be but they're approx 300kg each, share the load over the existing joists and it's probably fine?
Click to expand...
I don’t know. Just going with what the man with the letters after his name says. The engineer has okay’d the hanger and what I plan to do. So that’s the plan.

Next issue is getting two 3.8m 2x7 joists upstairs… no way they’ll go up the stairs so I think I’m going to have to take a pane of glass out the window.
 
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Rob_B said:
Cheaper to get a new boiler instead of moving the tank at this rate :D
Click to expand...
The boiler is going to be moved into the loft…. It’s a long long story. But basically my house is 1950s built. It has an original outbuilding attached to the back of the house. This is single skin single brick! A doorway has been knocked through internally to the outbuilding and it has: the only bathroom, the mains water goes in there, the boiler and cylinder are in there.

We want to knock it down and do a proper extension, but to do that I need to have in the main part of the house: a bathroom, and central heating. I’m also going to look at getting a new water main, because the current one I only get 9l/min which is crap.
 
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You've definitely gone OTT on this lol. I'd just sister them with some OSB screwed in!
 
Context if you care @dlockers and @Rob_B

My neighbours (mirrored semi detached), got planning permission 15 years ago for pretty much exactly what we want to do - they never built it though. The images below are from their application.

Here is the existing layout - you can see the single skin single brick part at the back has the mains water, and the boiler and cylinder as well as the only bathroom in the house.


This is what the planned layout will be:


Note this is my neighbours so it's mirrored, so the upstairs bathroom the tub is on the left in theirs but it's on the right in mine.
In that diagram I have already finished Bedroom 4 + 2. Bathroom is next, then Bedroom 3. Then save up to do the extension.

But the point is before that part at the back gets demolished I need in the main part of the house: a bathroom, a boiler + cylinder and mains water.
 
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Looks mega man. I didn't consider BC needed notifying about moving a bathroom (as you know I've moved mine from rear to front lol). I have also insulated more than 50% of the room but didn't bother, either. My span is ~2.2m though, not 3.7! So I can see why it was a valid question.

New layout looks brilliant.
 
dlockers said:
Looks mega man. I didn't consider BC needed notifying about moving a bathroom (as you know I've moved mine from rear to front lol). I have also insulated more than 50% of the room but didn't bother, either. My span is ~2.2m though, not 3.7! So I can see why it was a valid question.

New layout looks brilliant.
Click to expand...
From what I understand, if you're altering a bathroom where one already existed you're probably fine. But in my case there never was one so I have to get approval from BC. Even in your case, where you've moved it to a completely different location. Presumably all your first floor joists are the same size. So if they are strong enough to support a bathroom upstairs in one place, they should be strong enough to support a bathroom anywhere... but I'm not a structural engineer :D

It's a funny one with BC, it can only potentially be an issue when selling the house. And for that to happen the people buying the house have to notice that there has been a renovation and then ask a) "did they need to notify BC" and then if the answer is yes b) "did they?".

If they never ask the question then it's never an issue.
 
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the joist upgrade diagram just says screw/sister them not mentioning any additional end load support ??

what would be the practicality of installing the hanger, too - can you chisel out a slot at the required level, hopefully that aligns with the mortar, or, will you have to take out most of a brick and repack the gap.
 
jpaul said:
the joist upgrade diagram just says screw/sister them not mentioning any additional end load support ??

what would be the practicality of installing the hanger, too - can you chisel out a slot at the required level, hopefully that aligns with the mortar, or, will you have to take out most of a brick and repack the gap.
Click to expand...
That hanger I'm going to use, the flange lines up nicely with the existing mortar bed so should be fine.
 
Bump. Did this all over the weekend. Exposed it all:



Cut all the wires going through the existing joists. Extended them all and temporarily put them ‘over’ the joists so I can sister the new ones:



Raked out mortar. Cleaned out the hole. Fit the joist hangers. Mortared them in. Splodged a load of CT1 on the back of them for good measure.



Sistered the joists as per the engineers directions. Added noggins in the centre.





Now it’s on to getting a new water supply. Current one is shared, 70 years old, and only get 9l/min.

Dug a big hole where I plan to bring it into the house. From this:



To this:




Going to be tricky here. Water pipe has to be 750mm below ground. Where it goes into the house it has to go in 4 inch waste pipe and the pipe has to be insulated.

My footing bricks only go 1 foot below ground level and then there are foundations.

I’m hoping I can core drill in the footing bricks. Then 45 down past the foundations. Down to 750mm and then 45 flat.

Water board guy is coming Wednesday so I’ll run it by him then.

Next step on the bathroom floor is to expose the right hand side. Put noggins all the way across. Then ply the floor. Then build the stud walls for the bathroom and new boiler room.

I’ll keep this thread up to date.
 
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Nice work! Seems you're doing all the jobs I'd like to do in our place. Main bedroom is 4m x 4m and all suspended/full span. Quite bouncy, so I'd like to sister some joists or add noggings or both. Ideally I'd do it without fully taking up the floor though.

Does it feel much more solid now you've sistered up?
 
Took the week off to break the back of this. Just a reminder of the layout I'm aiming for:
rTWBhYh.png


Exposed the other joists, added noggins all the way across, also made myself a little platform in the middle to work off with the cut floorboards.
fW20znO.jpeg


First sheet of 18mm Marine Ply down. Screws every 100mm, seems like a lot, but when you think 6 inch floorboards had 2 fixings each, it's not actually that many.
ylkc8ND.jpeg


All 3 sheets down:
HCDiiOq.jpeg


Marking the layout of boiler cupboard and new bathroom entrance on the floor with tape:
MajHiHE.jpeg


And this is where I got to today before it was bedtime for the little boy:
Nye9kV5.jpeg

VwhDPpd.jpeg


Just needs a few noggins, and doubling up the studs where the door openings are.

Also need to cut an access hole in the ply for the gas/water/central heating flow + return, and new sockets for the boiler to go in, which will mean busting out the circular saw. I hate the thing, so loud, much prefer using a hand saw. I'm getting reasonably good at cutting square now, but I'm nowhere near a carpenter :D

It might not seem like much in a week, but what is not shown is all the noggins I had to put in the loft, and under the ply etc. Disconnecting the light switch to remove the old plate from the ceiling for the old wall. Removing one of the lights because the boiler room walls overlaps it, putting a plasterboard patch in etc. It's all the 'small things' that take time, I built all that studwork today in about 6 hours.Pain in the arse. I also got a massive splinter go up under my finger nail :(
 
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