New lintel/flat roof issues

[Cassie]

I’ll take small wins feltwell-starting to dry is better than continuing to rot! 9 inch wall then = 9 months at least. I’ve been stuffing up the worst of the holes and pointing from the bottom up (I know that’s the wrong way round!) but I won’t be pointing much higher or replastering for some time yet, no point until roof fixed because walls will continue to get sodden. Maybe the dank porch cave can become a “feature” for the foreseeable future

 

[noj]

The positive (not huge, admittedly) is that a moist, but drying substrate is absolutely perfect for carbonating new lime pointing

 

[Cassie]

Thanks noj-again, I’ll take the small wins

 

[Zebra]

Don't give up that easily Cassie. You've answered the first question - how do I support it? - "buggered if I know"... But if you can't figure it out then chances are a builder won't either. You'll end up paying a lot of money to watch in horror as they either a) smash something you didn't want broken and say "well what else was I going to do?", b) prop it off the wooden staircase and hope for the best, or c) pull the old lintel out and see what falls down.
If the existing timber is rotten, then how much support is it actually offering? You'd have nothing to lose if you did just try to prop it off the stairs, with another support under the stairs (with a small hole in the ceiling underneath if necessary) and then just gave the old lintel a bit of a poke.
However, I'm not there and I can't say what you should do, and I don't know how hard it really is, so I don't want to be giving you advice based on so little information so perhaps I'll shut up and perhaps you're right it is time to get a professional in.

 

[a twig]

More good news is that he doesn’t think it needs propping, as probably only the front half is shot-that can be removed leaving the good bit in to hold anything up that might drop while a new lintel, placed either on concrete pads or new bricks is inserted. Even if it all needs to come out, the arch should hold most of it up

I cannot see how I can safely prop the stuff above the lintel. On one side there’s wooden steps (bouncy) on a suspended timber floor, with a load bearing wall underneath, so can’t be supported from the ground. On the other (hall) side, 18” of brick until the fancy cornice. Neither acrows, needles or no-more-props seem viable. I have to bite the bullet and get someone in.

Sorry, I feel like I’m missing something, I thought the structural engineer said it didn’t need propping?

 

[Cassie]

He said it probably didn’t need propping. I left out a crucial word!

 

[paulc]

There are other options to propping a wall when acros aren't practical. Steel plates on each side of the wall, bolted together have been used. There are some devices like No more props that have been developed on that method.

Looking at some photos of Cassie's porch*, steel plates bolted to the wall may well be a viable option. Or if the render can be hacked back, some of those brick brace gadgets could be used. There is a substantial pier (presumably, a pair) that could be used to rest a temporary support on and brace the wall off that.
Have done a couple of lintels here (just the outer leaf of brickwork) that were just over 6' wide. Got away with minimal support from a 3x2 wedged in the middle of the span.

*) https://www.periodproperty.co.uk/fo...er-structural-or-not.17544/page-2#post-235248

 

[Cassie]

Don't give up that easily Cassie. You've answered the first question - how do I support it? - "buggered if I know"... But if you can't figure it out then chances are a builder won't either. You'll end up paying a lot of money to watch in horror as they either a) smash something you didn't want broken and say "well what else was I going to do?", b) prop it off the wooden staircase and hope for the best, or c) pull the old lintel out and see what falls down.
If the existing timber is rotten, then how much support is it actually offering? You'd have nothing to lose if you did just try to prop it off the stairs, with another support under the stairs (with a small hole in the ceiling underneath if necessary) and then just gave the old lintel a bit of a poke.
However, I'm not there and I can't say what you should do, and I don't know how hard it really is, so I don't want to be giving you advice based on so little information so perhaps I'll shut up and perhaps you're right it is time to get a professional in.

Thanks zebra. I had thought about making a hole in the lath and plaster ceiling below and maybe propping the joists, but I’ve a horrible feeling I’ll find rotten ends and therefore open another can of worms. The room below contains 2 gas boilers and the compression vessel thingy. Eventually the weird 2 boiler system needs replacing, but it’s still working ok so not urgent! There’s also a big sink on a brick plinth against the house wall which would need removing to get props in. Not insurmountable. Perhaps you’re right-the lintel/former doesn't look like it’s doing much, but there are bricks resting on it, and from what feltwell said about self-corbelling maybe the worst that can happen is a few bricks fall out. But maybe a lot more! To get the new lintel into the 9 inch brick walls far enough and insert padstones or new bricks, I’d have to make some bigger holes, wait for mortar to dry etc. Making holes in the walls with nothing supporting the adjacent wall feels a bit scary I’m rambling now, sorry!

 

[stuart45]

If the joist ends are rotten, it's better if you find out now when the work is in progress.

 

[Cassie]

If the joist ends are rotten, it's better if you find out now when the work is in progress.

You are of course right Stuart! And if I find rotten ends I guess I’d need to remove the steps above anyway to repair? Unless it can be done from below?? With no steps and the floor up, propping the lintel would be less of an issue perhaps, although the height from ground level to lintel is maybe 20ft
I’m definitely in unchartered waters here, I feel out of my depth

 

[Cassie]

Looking at some photos of Cassie's porch*, steel plates bolted to the wall may well be a viable option. Or if the render can be hacked back, some of those brick brace gadgets could be used. There is a substantial pier (presumably, a pair) that could be used to rest a temporary support on and brace the wall off that.
Have done a couple of lintels here (just the outer leaf of brickwork) that were just over 6' wide. Got away with minimal support from a 3x2 wedged in the middle of the span.

*) https://www.periodproperty.co.uk/fo...er-structural-or-not.17544/page-2#post-235248

Thanks paul. Please forgive my ignorance, where do the steel plates go?

 

[stuart45]

I'm having a bit of trouble visualising the layout of the area and the steps Cassie. Have you got any more photos of the steps and a bit further back of the extetior?

 

[Cassie]

I'm having a bit of trouble visualising the layout of the area and the steps Cassie. Have you got any more photos of the steps and a bit further back of the extetior?

Hi Stuart , I don’t know how to insert into text, so I’ll attach. The photo is taken from inside the porch. To the left is the front door, behind me and to my left are windows. There are 2 wooden steps going up into the hall. The dodgy lintel is above the white glazed door at the top . of the steps. That’s as far back as I can get-it’s less than 6ft from the bottom of the steps to the wall opposite

 

[Cassie]

Argh! Behind me and to my right are windows

 

[Cassie]

For good measure, here is what’s below. The strange gas pipe floating around the ceiling is being disconnected shortly. The room is an odd shape-square on the left as you look at it, but going into a smaller angle in the back right corner. Next door is a bathroom, so maybe the room was divided to accommodate that, although the sink looks like it’s been there a while! In the bathroom next door, there is clearly something going on with the ceiling , I suspect it’s all part of the same issue with flat roof drainage. Because of the funny room shape I don’t know where the joist ends would be.

 

[stuart45]

To me that looks to be easy enough to prop if needed. I've propped off timber floors before when needed, by putting down timber, or scaffold boards to spread the load.
When using needles and acros, the acros can be well back from the wall, so they could be past the steps onto the porch floor.

 

[Cassie]

Thanks Stuart. My (limited!) understanding is that needles need to be inserted through the wall a couple of courses above the lintel-is that correct? In which case, I’d need to do it from the hall side and maybe use strongboys instead of needles as the bricks above the lintel on the porch side aren’t accessible from inside

 

[stuart45]

Strongboys on the inside would work. Put a strong timber under them to spread the load. Underneath you would have to set them back a bit.
If there's an arch there it probably doesn't really need much.

 

[Cubist]

If I recall correctly Cassie, the timber that needs to be replaced is immediately above the joist (the timber you have stripped of render) that we can see at the top of this latest photo. Is that correct?

If so, then the supports have to be installed from the side from which the photo is taken and.... the new lintel has to be installed from inside the hall. To do that I suspect it may be necessary to sacrifice some, maybe a lot, of the internal plasterwork.

 

[Cassie]

Yes that’s correct cubist. So propping from the hall side not possible? On that side there’s maybe 18” of plaster (lime onto brick) under the ceiling. This needs redoing anyway as as the wet has penetrated and it’s in poor condition. The cornice comes down the wall maybe 4 inches. I’d be sad to see that go as although it’s damaged (repairable) in places, it goes round the whole hall