Hi there fellow period property lovers! Since moving into our new mid-terrace Victorian in east London and starting to assemble our furniture, I’ve noticed that there is a noticeable downward slope to the left hand side on every floor. There are no obvious signs of subsidence, and I have had floor specialists come out to check the joists (we got very mixed advice - some saying “these beams have been here before you and will outlive you” to others suggesting we need to rip up everything and relay our floors. From reading up online it sounds like it can be normal for a house to have historically settled in one direction and tilt down. Is this true? Or is this just the early signs of subsidence. How much slope is too much slope to tolerate? Would love your thoughts. Thank you
- Thread starter Rhep90
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Toby Newell
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Hi, what is the runout?
If it makes you feel any better, I finished a 1500 cottage last year with a pine and oak floor with a 300mm runout over 4 metres.
In general I talk people out of levelling, as it is very expensive and very easy to damage the boards, if the runout is less rhan 100mm.
Current job, 1550 cottage, mostly oak boards, room was 200mm out, luckily the framer came in and saved my sanity, dropped the ceiling and lifted the joists.
Where in East London? I was born in E5, done many jobs there, there is always subsidence in N and E London.
London is an alluvial bowl of clay on a bed of chalk, its always moving.
Also your joists could of bent in the middle due to excessive notching and removal of strutting for services (cables, pipes) accommodation, or could have dropped due to decay of wood or masonary at the ends. Either they are pocketed (set in hole in wall) or rest on a seat beam or plate (ground floor)
Unless you have damp issues, obvious rot / pest damage / or weakness on one side it's probably ok.
You can sister joists if the dip is in the middle, but for one side cutting firrings (tapers) is normally best, only issue is lifting the boards, if they are long all will need to come up. Also many boards run under walls which doesn't help. You can get pre cut firrings from selected timber yards, cutting them yourself is only for a very confident DIYer. No one likes cutting them on a table saw or with a circular saw, the probability of kick back is very high when cutting very thick timbers at an angle (please don't google!)
If it makes you feel any better, I finished a 1500 cottage last year with a pine and oak floor with a 300mm runout over 4 metres.
In general I talk people out of levelling, as it is very expensive and very easy to damage the boards, if the runout is less rhan 100mm.
Current job, 1550 cottage, mostly oak boards, room was 200mm out, luckily the framer came in and saved my sanity, dropped the ceiling and lifted the joists.
Where in East London? I was born in E5, done many jobs there, there is always subsidence in N and E London.
London is an alluvial bowl of clay on a bed of chalk, its always moving.
Also your joists could of bent in the middle due to excessive notching and removal of strutting for services (cables, pipes) accommodation, or could have dropped due to decay of wood or masonary at the ends. Either they are pocketed (set in hole in wall) or rest on a seat beam or plate (ground floor)
Unless you have damp issues, obvious rot / pest damage / or weakness on one side it's probably ok.
You can sister joists if the dip is in the middle, but for one side cutting firrings (tapers) is normally best, only issue is lifting the boards, if they are long all will need to come up. Also many boards run under walls which doesn't help. You can get pre cut firrings from selected timber yards, cutting them yourself is only for a very confident DIYer. No one likes cutting them on a table saw or with a circular saw, the probability of kick back is very high when cutting very thick timbers at an angle (please don't google!)
Hi Toby, might be a silly question after your wonderfully detailed response, but how do you measure the runout accurately? I’d say it’s definitely way less than 100mm over 4m it’s probably at best half that (just visually). The joists are pocketed here, all the professionals who have looked have said there’s no damp or rot down in the coal cellar at all so don’t think that’s an issue! The previous cowboy owner did cut one of them though to make stairs down to the basement…nobody has said that’s a specific immediate issue but it does make me worried about the overall structure.
The property is in E11 btw and I can see signs of subsidence in other properties around here so I’m not surprised to hear that at all!
The property is in E11 btw and I can see signs of subsidence in other properties around here so I’m not surprised to hear that at all!
Toby Newell
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- Surrey
Get yourself a straight edge you can buy a long spirit level of 1.8m, alternatively you can buy a shorter spirit level and something straight to rest it on, like a 2 x 4in joist, if you can fit it in your vehicle, you would need to check it for straightness as many are warped, either that or any long straight thing.
Prop up the low end until the level is flat then measure the height.
The cheapest maybe to buy a bricklayers line level that clips onto a string, buy some level string (normally fluoro yellow) fix it to the high side, then run it to the low side, pull it taught and move until the bubble is level, that height is your runout.
Two inches is perfectly normal and nothing to worry about.
Can you see the joists from underneath in the basement? If so please send pictures. Cutting joists to put in a staircase may or may not be an issue depending upon whether the person doing so framed the cut out area with noggins to bridge the cut joists and help spread the load, if they didn't then this certainly could be the problem. It's not ideal, but unless the joists and floor are weak and / or move when you walk over them, then it's probably ok. If you wanted to strengthen the area you could possibly do so from below, this would not ameliorate the current drop, but mitigate any further drop in the future. If you wanted to eliminate the drop that would entail a lot of work removing the floor and for 50mm I would not advise it.
I have worked with and quoted for many 'professionals' some of whom were architects and project managers on multimillion pound projects on internationally significant buildings, including EH. Many of whom had little clue. Professional simply means they get paid for the work they do. Our last Prime minister and Chancellor are professionals, at the very pinicle of their professions although you might not want to take financial advice from them.
The older I get the more I realise the less I know. Professional is a meaningless term. Technically I am an expert because I have a large amount of knowledge and skills, several decades, in my field. However, I prefer to think of myself now as a very advanced amateur with severe mission creep.
Fortunately most advice is free, unfortunately most of it is worth as much.
I think in todays world, everyone is an expert and misinformation is promulgated by lazy individuals online, including so called experts, Wikipedia, journalists, magazines and institutions. Evaluating facts is now a science in itself and should be taught in schools and in evening classes for adults.
On my website I endeavour to promote facts, it has taken me sometimes several hours or days down a surfing rabbit hole to research one sentance to ensure it is correct.
Your slope is probably ok, if you have joists cut and a big hole in your floor that's probably not, but it's also something not to worry about and should be easy to remedy if you can get access from below.
Essentially you want to connect the joists either side of the cut with timbers (noggins) using C24 timber. The rule is to get someone to cut these very snug (most people don't bother) a very tight fit is important because for butt joints (flat to flat, no overlap or insertion) the load is transferred via friction. Adhesive and fixings primarily restrict movement and hold in place. Fixings can pull members tighter increasing friction but a friction fit that requires gentle knocking in still best to start.
A cheap electric mitre saw, a pencil, measure and mallet is all you need, and a bit of patience.
You can. Never. Have too many noggins...
Prop up the low end until the level is flat then measure the height.
The cheapest maybe to buy a bricklayers line level that clips onto a string, buy some level string (normally fluoro yellow) fix it to the high side, then run it to the low side, pull it taught and move until the bubble is level, that height is your runout.
Two inches is perfectly normal and nothing to worry about.
Can you see the joists from underneath in the basement? If so please send pictures. Cutting joists to put in a staircase may or may not be an issue depending upon whether the person doing so framed the cut out area with noggins to bridge the cut joists and help spread the load, if they didn't then this certainly could be the problem. It's not ideal, but unless the joists and floor are weak and / or move when you walk over them, then it's probably ok. If you wanted to strengthen the area you could possibly do so from below, this would not ameliorate the current drop, but mitigate any further drop in the future. If you wanted to eliminate the drop that would entail a lot of work removing the floor and for 50mm I would not advise it.
I have worked with and quoted for many 'professionals' some of whom were architects and project managers on multimillion pound projects on internationally significant buildings, including EH. Many of whom had little clue. Professional simply means they get paid for the work they do. Our last Prime minister and Chancellor are professionals, at the very pinicle of their professions although you might not want to take financial advice from them.
The older I get the more I realise the less I know. Professional is a meaningless term. Technically I am an expert because I have a large amount of knowledge and skills, several decades, in my field. However, I prefer to think of myself now as a very advanced amateur with severe mission creep.
Fortunately most advice is free, unfortunately most of it is worth as much.
I think in todays world, everyone is an expert and misinformation is promulgated by lazy individuals online, including so called experts, Wikipedia, journalists, magazines and institutions. Evaluating facts is now a science in itself and should be taught in schools and in evening classes for adults.
On my website I endeavour to promote facts, it has taken me sometimes several hours or days down a surfing rabbit hole to research one sentance to ensure it is correct.
Your slope is probably ok, if you have joists cut and a big hole in your floor that's probably not, but it's also something not to worry about and should be easy to remedy if you can get access from below.
Essentially you want to connect the joists either side of the cut with timbers (noggins) using C24 timber. The rule is to get someone to cut these very snug (most people don't bother) a very tight fit is important because for butt joints (flat to flat, no overlap or insertion) the load is transferred via friction. Adhesive and fixings primarily restrict movement and hold in place. Fixings can pull members tighter increasing friction but a friction fit that requires gentle knocking in still best to start.
A cheap electric mitre saw, a pencil, measure and mallet is all you need, and a bit of patience.
You can. Never. Have too many noggins...
Last edited:
Hi Toby thanks so much for this detailed response and the photos! So from digging around the coal cellar - here are some photos. It appears that the structure seems to be a mix of pocketed into the wall and some king of brick/cement supporting stack underneath? The beams pocketed into the wall do not stretch the whole way across the floor of that makes sense? Excuse my lack of verbiage in this space I’m a total newbie to all things construction - this house has certainly been a school of hard knocks in coming up to speed. There is no sign that this cut foundational joist is supported behind the wood beam holding it up. A builder I have come to trust a lot came and looked at it and told me that though odd, this should be fine in terms of support. Do you agree? 
Toby Newell
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- Surrey
Right, I'm sorry but I cannot really make head nor tail of much from brief glimpses of random bits of wood.
From what I can see, the brickwork in the first photo doesn't look great, to be fair it could be awful bricklaying, or could simply be awful repointing of decayed mortar, or addition of squirty foam to fill gaps, it's hard to tell but doesn't look neat. A traditional pocket, is often a regular sized hole made in the laying of the bricks. It seems to be stuck into a large splodge of mortar, although again this could be filler over a neat hole. This isn't necessarily super great either as the basement may be below ground level and ideally you would want some sort of dpm / bitumen paper / slate to isolate the timber from possible damp and not to bridge that with a bowl of mortar porridge.
Beam end in pic 1 doesn't look deflected, rotted or decayed.
Pic 2 I can't really see much.
Pic 3 Is obviously wrong, how wrong one could not tell without seeing where the beam was going. The support, randomly speared with screws which may or may not be doing much, at least is fairly chonky. I hope it is firmly attached to the ground at the other end and not flapping about.
The builder who said pic 3 situation is 'ok' should of qualified that with 'beams normally go from one place to the other, the other being a joining or supporting structure. They should have also added that air is neither the former nor the latter. The joining method is extremely poor, it is not clear the screws penetrate much. There is perfect room to fit straps or a joining plate. As an amateur I am very unimpressed at that level of work.
Now without seeing plans and / or photos of where that beam was heading it is not possible to state whether it is simply 'not ideal' or 'not ideal and actually needs something done about it'.
I am in no way an expert in surveying, engineering, construction or timber framing. I am just a bloke who has seen a lot of stuff, in a lot of houses and has taught himself how to repair stuff, mostly floors and stairs and sub floors.
I can say however that my spidey sense is tingling and it says this really doesn't look great and seems indicative of very lax work, which normally means you should expect more areas of concern.
I would suspect something could and should be done to at least tidy up the area. The support should be strapped, checked for plumb (right angle to the floor) and soundness (snug fit to the floor) Also check where the cut beam goes. You may want to bridge the next beams accross with noggins to tie the structure back together. I presume you took pic 3 with wide angle lens and the risers are not comically large in real life.
Hopefully someone more knowledgeable will chime in, perhaps Malcolm or Cubist, they can request what to photograph or draw out and tell you whether it's ok and tell you whether they think you should contact a structural engineer / surveyor.
Don't worry, it could be totally ok. In general though, builders that have high competance like to execute work that is both functional and neat. When you see an abundance of mess and jank you are also oft to find things which are incorrect, some of which may require remedy.
From what I can see, the brickwork in the first photo doesn't look great, to be fair it could be awful bricklaying, or could simply be awful repointing of decayed mortar, or addition of squirty foam to fill gaps, it's hard to tell but doesn't look neat. A traditional pocket, is often a regular sized hole made in the laying of the bricks. It seems to be stuck into a large splodge of mortar, although again this could be filler over a neat hole. This isn't necessarily super great either as the basement may be below ground level and ideally you would want some sort of dpm / bitumen paper / slate to isolate the timber from possible damp and not to bridge that with a bowl of mortar porridge.
Beam end in pic 1 doesn't look deflected, rotted or decayed.
Pic 2 I can't really see much.
Pic 3 Is obviously wrong, how wrong one could not tell without seeing where the beam was going. The support, randomly speared with screws which may or may not be doing much, at least is fairly chonky. I hope it is firmly attached to the ground at the other end and not flapping about.
The builder who said pic 3 situation is 'ok' should of qualified that with 'beams normally go from one place to the other, the other being a joining or supporting structure. They should have also added that air is neither the former nor the latter. The joining method is extremely poor, it is not clear the screws penetrate much. There is perfect room to fit straps or a joining plate. As an amateur I am very unimpressed at that level of work.
Now without seeing plans and / or photos of where that beam was heading it is not possible to state whether it is simply 'not ideal' or 'not ideal and actually needs something done about it'.
I am in no way an expert in surveying, engineering, construction or timber framing. I am just a bloke who has seen a lot of stuff, in a lot of houses and has taught himself how to repair stuff, mostly floors and stairs and sub floors.
I can say however that my spidey sense is tingling and it says this really doesn't look great and seems indicative of very lax work, which normally means you should expect more areas of concern.
I would suspect something could and should be done to at least tidy up the area. The support should be strapped, checked for plumb (right angle to the floor) and soundness (snug fit to the floor) Also check where the cut beam goes. You may want to bridge the next beams accross with noggins to tie the structure back together. I presume you took pic 3 with wide angle lens and the risers are not comically large in real life.
Hopefully someone more knowledgeable will chime in, perhaps Malcolm or Cubist, they can request what to photograph or draw out and tell you whether it's ok and tell you whether they think you should contact a structural engineer / surveyor.
Don't worry, it could be totally ok. In general though, builders that have high competance like to execute work that is both functional and neat. When you see an abundance of mess and jank you are also oft to find things which are incorrect, some of which may require remedy.