A corner of my house may be sinking:
I had to cut almost half an inch at an angle off a sticky door,
maybe six inches over ten years?
Is there a tool to measure the slope or position of the walls very accurately and then again a year later?
Yep, a theodolite
You might find that an inclinometer app on the smartphone
works quite well if there is something that you can put the
smartphone on that doesn’t move by itself.
Or a laser level that you can put some marks on the wall and
then do that a year later and compare the two sets of marks.
After the last two hot summers, I have some of that going on here.
Not quite that bad here!
Things like cracks you can measure with three points fixed to either
side and above/below the crack. Then take readings with a caliper. That
gives relative vertical and lateral movement.
Marking points off on a wall from a projected laser level line can give
an indication of up down movement of whole walls etc.
Slope you could do with one of those digital tilt meters used for
measuring blade angles on table saws. (some of the posher laser tape
measures can also do inclination measurement)
I have a blob of (I think) Plaster of Paris molded over a crack, date scratched
into the surface.
If the crack underneath moves, the blob cracks and the width and direction of
the crack show amount and direction of movement...
Cheap, and requires no record-keeping.
On Wednesday, 9 October 2019 22:32:04 UTC+1, George Miles wrote:
If it's that much, a decent spirit level or a plumb bob should do the job.
Check verticals and horizontals
There will be cracks in masonry, you should cement/glue glass telltales over them and see if they break.
Or just fill cracks with cement and see if it opens again.
Any repairs needed will be expensive.
Any wall seriously out of plumb will need shoring to prevent collapse/injury to inhabitants.
That's a worrying amount of change. Clay soil or mining area?
It is a timber framed building as is common in areas with subsidence
problems like Cheshire and are there any signs of cracks in the walls?
A plumb bob on a long string is as good as anything for a quick check.
A surveyor will put transparent gauges one on either side of any crack
epoxied to the wall and monitor how it changes with time. They can also
put reflective tags on and monitor how they move relative to some datum.
On Wed, 9 Oct 2019 14:32:00 -0700 (PDT), George Miles
Apart from measuring it (plenty of good suggestions here), I remember
seeing on TV a few years ago on one of the house renovation or auction
programmes that the owner had a corner of his house dropping. The
cause was found to be a damaged and leaking drain, that was slowly
eroding away the soil on that corner, rather than mining subsidence or
'heave'. The drain was repaired, obviously, but I can't remember
whether the corner was underpinned or not.
Homes under the Hammer, (or could have been Kirsty and Phil), did a
program about a house in Sheffield with many large trees around
the house and some nasty subsidence cracks and destroyed drains.
They bought it, persuaded the council to allow some trees to
be removed (conservation area), replaced all the drains and
over the next 12 to 18 months, all the filler used to hide
the internal cracks got squeezed back out as the soil
under the house assumed its original water content that the
tree roots had sucked out, and the ground heaved back up.
Thanks for the replies,
I've got to think more on it,
make diagrams of the building,
and measure the angles everywhere,
remember my school geometry,
get more advice and ideas from this group!
I'm guessing a plumb line indoors will be more accurate than a phone GPS or spirit level to get a true level, or maybe my two water jars and hose !
Roger Skill Builder was talking about them a few weeks back at
On Wednesday, October 9, 2019 at 10:32:04 PM UTC+1, George Miles wrote:
Having watched many programs of Homes under the Hammer, plus
Kirst and Phil, the message seems to be, if a crack on an
outside wall also occurs on an internal wall in the same spot,
or if it goes diagonally down a wall, it could be serious.
If just a door frame is moving, could it be the slab at fault ?.
Lots of houses were built using power station ash as part of the
concrete used to pour slabs and these can chemically interact with
Any trees nearby ?, or evidence of sinking, tilting paths that
might indicate a broken drain ?.
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