Hi,I had a single storey extension built one year ago,planning application was applied for and granted,extension was built with regular visits from local council inspector,and completion certificate issued when extension was finished,now I have large cracks developing and definite signs of movement,my question is with whom does the responsibility lie if I need remedial work,is it my builder or the council who said that the land was good and the architects drawings etc was ok.
Extension movement
- Thread starter Brett8356
- Start date
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Questions?
Did the Architect employ an Engineer to design the foundations? Who designed the Foundations to the satisfaction of the Local Authority
Did the Architect or if employed an Engineer Supervise the Foundation work?
Was there a Soils Investigation Report and bore hole test undertaken, if so who instructed this?
What you need to establish is who designed the Foundations? and what tests, such as Soils Investigations were undertaken, this to determine what the Foundation design will be.
Ken.
Did the Architect employ an Engineer to design the foundations? Who designed the Foundations to the satisfaction of the Local Authority
Did the Architect or if employed an Engineer Supervise the Foundation work?
Was there a Soils Investigation Report and bore hole test
What you need to establish is who designed the Foundations? and what tests, such as Soils Investigations were undertaken, this to determine what the Foundation design will be.
Ken.
How do you know the cracks are 'definite signs of movement'?
Internally,Week on week I have cracks either developing or appearing in new places,not just hairlines emanating from corners of velux's but vertically down the corners of the walls,from top to bottom and externally large cracks where new extension meets old property as if it's trying to pull away from existing building.if you look at the floor internally and draw a parallel to the solid oak skirting the floor sags to about twenty mm in the middle. I hope I'm wrong but I would like to be sure of my course of action should my worst fears be proved correct
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Ken,
As far as I am aware no soil investigations were carried out nor requested,i do recall my builder having to wait for the building inspector to come and examine his footing excavations before he could pour the concrete,surely the council consider soil conditions upon receipt of architects drawings prior to consent?,thereby giving the go ahead in terms of subsoil condition,pardon the lingo,I'm a mech eng,not civil biased
As far as I am aware no soil investigations were carried out nor requested,i do recall my builder having to wait for the building inspector to come and examine his footing excavations before he could pour the concrete,surely the council consider soil conditions upon receipt of architects drawings prior to consent?,thereby giving the go ahead in terms of subsoil condition,pardon the lingo,I'm a mech eng,not civil biased
The council may well have inspected the footings prior to pouring but they won't be held responsible. As above the is a design issue with the foundations it'll come down to whoever designed them.
It's just concerning me that as a layman you play by the rules and try to do everything correctly,ie architect,planning permission,reputable builder,surely after a year if you are having problems the financial responsibility should not be on you as the householder to Carry out major remedial works,
D
Deleted 224857
Three foot deep footing???
Seasonal movement and weather effected movement, in clay soil conditions are not unusual.
Are you on clay?
Are these cracks settlement issues?
Thermal?
Have you had a laser level on the upright elevations?
Are you on clay?
Are these cracks settlement issues?
Thermal?
Have you had a laser level on the upright elevations?
You say you observed the soil coming out of the trench and it looked good.
http://www.planningportal.gov.uk/uploads/br/BR_PDF_AD_A_2010.PDF
Page 35 of the document. How would you describe the soil? What was the width of the foundation? Was it strip or full fill?
Councils don't even do the thumb test. They just look at it and say yep, that's a big hole.
http://www.planningportal.gov.uk/uploads/br/BR_PDF_AD_A_2010.PDF
Page 35 of the document. How would you describe the soil? What was the width of the foundation? Was it strip or full fill?
Councils don't even do the thumb test. They just look at it and say yep, that's a big hole.
Firstly you need to establish what category of cracking you have by measuring the cracks. BRE Digest 251 is the definitive guide for defining crack category and how serious they are. Category 0 & 1 would only be defined as decorative cracks. I've inserted a link to this document. http://www.bhsurveyors.co.uk/Resources/BRE_Digest_251_Assessment_of_damage_in_low-rise_buildings.pdf
You next need to establish whether movement is 'progressive and ongoing' by putting crack monitoring in place, I generally do this using glued demec studs and a vernier calliper. You should also rule out any potential issues with sub-soil leaks, foul drains, incoming water mains.
It is not unusual to get differential settlement cracks between old and wall junction details, especially when brickwork hasn't been properly toothed in. Again, it is more about the crack severity and whether movement is proven to be progressive and ongoing.
As someone has previously pointed out, there are lots of reasons for cracking in new buildings, minor settlement & shrinkage cracks are common and differential expansion can be another cause.
If the building is moving then the next stage is digging a trial pit to establish the depth of the foundations. It can also be very useful to have distortion survey carried out but you'll need a Chartered surveyor or building engineer for this.
You next need to establish whether movement is 'progressive and ongoing' by putting crack monitoring in place, I generally do this using glued demec studs and a vernier calliper. You should also rule out any potential issues with sub-soil leaks, foul drains, incoming water mains.
It is not unusual to get differential settlement cracks between old and wall junction details, especially when brickwork hasn't been properly toothed in. Again, it is more about the crack severity and whether movement is proven to be progressive and ongoing.
As someone has previously pointed out, there are lots of reasons for cracking in new buildings, minor settlement & shrinkage cracks are common and differential expansion can be another cause.
If the building is moving then the next stage is digging a trial pit to establish the depth of the foundations. It can also be very useful to have distortion survey carried out but you'll need a Chartered surveyor or building engineer for this.
Liability can be difficult to determine. Firstly as Joe states above, you need to determine the cause.
Then you will need to see if it's a design issue, or a quality/building issue.
You do need an independent report, and this should be by a structural engineer, or a building surveyor with good structural knowledge. You need to brief them that you require an opinion on the design and the build.
Many people fall in to the trap of assuming that the council will be checking the work for quality, and can't understand how things like this happen afterwards. But it's relatively common and the council have no liability.
Check if your home insurance will cover the cost of a report. Don't use any offered by the insurer though, they need to be independent.
Many people who do plans for domestic extensions detail a simple strip foundation, and then annotate it with 'foundation subject to ground conditions' or some such wording.
The plan-drawer may also not supervise the work, but simply just provide plans and no more.
If this does turn out to be a foundation issue, then as a matter of interest, who would be liable?
The designer (plan drawer) would be responsible, unless he has delegated design to another.
The designer could argue that he has only been instructed to merely draw plans to pass building regulations, but there must surely be an expectation that the customer wanted a suitable extension in addition to just meeting building regulations. It might make an interesting argument, and may come down to any contract terms or what was discussed between the OP and the designer.
The designer can't delegate design to the building control surveyor with one of those "depth to the satisfaction of" statements, but he could delegate it to the builder with such a statement "To be constructed to BS 8004" for instance .
On the basis that the designer or builder should have designed suitable foundations, or arranged for specialist design if outside his competence, then the OP would have to prove that the foundations were inadequate and the designer/builder negligent. It may be that the foundations were designed correctly, and not negligently even if they have moved.
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