I'm not sure where the starting point should be and who to contact first. So, I wish to hear your expertise. I think getting builders in for their views is possibly not ideal since there maybe conflict of interest.
I want to have peace of mind about what caused those hairline cracks and bowed floor joists i.e. whether they are going to get worst quickly; and what options we have. If we do something before it got serious, it will probably save us in long run.
In brief, I bought my first house 5 months ago. It’s a 3-bed terraced house in Northumberland Heath, London Bexley. The house was built in the 1950s. Its first floor is out-dated but it's not much of an issue. The issue is that I noticed couple of hairline cracks started appearing on the internal wall as well as external wall. And about 2/3 of the house upstairs from front to back, the floor joists is uneven and like they're bowed.
We plan to completely refurbish and minor alter the upstairs and now we are not even sure if our savings is enough now considering the additional cost to rectify those issue. Hence, I also want to have a good educated costing for it – maybe not too detailed but not just ‘finger-in-the-air’ guess and for things I wish to do to refurbish our home. Once we have a clear cost, we can prioritise what to do first and whether to take out unnecessary bits.
1) Is subsidence common to mid-terraced house?
2) Can all existing floor joists be leveled or replaced for a period home? Is it a simple process or a really expensive exercise?
3) Are all movements as same as subsidence/heave/landslip? Should I get insurance company involved for hairline cracks?
4) Are architectural services section also included structural engineers to provide the services including the costing, I wish to have above?
5) Are you guys the best point to start for my situation or would the job be too small for you?
Thanks in advance for your time
Are you a tradesperson and able to answer this question?
Hi
I will try to answer your points in running order
1. It is possible for subsidence to occur in any type of property most likely as a result of collapsed drains or tree root damage rather than adverse ground conditions especially on older properties. As you report cracks are only hairline it is not likely to be subsidence but more like thermal movement or similar.
2. It could well be possible to level out the joists with packing strips / over laying with plywood or worst case insert replacement joists. Biggest problem with this will be working around any electrical / plumbing services that may pass through the existing joists
3. Structural movement can be a result of several factors not just subsidence. As I mentioned in point 1 thermal movement is one, lintel failure (especially if timber) is another if cracking is adjacent to window / door openings, introduction of central heating in previously unheated property, timber decay to joists if subjected to long term wet / damp or poor ventilation etc etc. Heave is only a potential problem in clay soils especially if nearby trees have been felled and landslip in steep terrain.
4. Some practices can offer both architectural and structural services although typically they are separate entities. You would need a quantity survey to provide you with independent costings if not getting actual quotes from builders.
5. I would advice that in first instance you have a structural engineer carry out a survey / assessment of the issues you have raised. They will be able to identify likely causes and any remedial works required. Once you have these details you can then invite suitable builders to quote
Regards
David
Hi.
Yes, we agree that your best course is to get a Structural Engineer to look at it and get details of the work that needs to be done.
1. The cracks in the wall are an issue and can be caused by subsidence, heave or land slip. If the soil is clay then heave can be a problem as clay expands and contracts with moisture and the forces are considerable. Poor drainage, inadequate foundations, leaking gutters, etc. will all exacerbate this. To check the foundation, dig a test pit at the bottom of the affected walls and measure the depth of the foundation. The walls can be underpinned if necessary and we would recommend a specialist firm to do this work.
2. Your joists should not be sagging and this can be caused by the joists not being a sufficient depth. Or, if they are "pocketed" into the walls they can rot at the ends. Lift the floor boards and determine the size of the joists. As a rule of thumb, if the span of the joists is 12ft. you will need at least a 6"x2" joist and ideally with 400mm spacing between them. A 14ft. span would need at least 7"x2" joists. If you replace all the joists this will mean a new ceiling on the floor below and any cabling and pipes will need to be replaced or supported while you do the work.
If the joists are sound and fit for purpose then you could pack out the floor boards above them to level the floor but if they are sagging it sounds like they need replacing.
3. Hairline cracks could simply be plaster cracks which are normal and no cause for concern, simply fill and paint them. But if they are near cracks in the external wall then movement in the wall is the most likely cause.
4. SEs are normally separate from Architects and it sounds like you need an SE more than an Architect. Ask them to draw up a spec for the work that needs to be done and then ask Builders to quote for the work based on this.
5. A good Builder should be happy to quote for the work and it's likely to be a fairly substantial job.
Good luck.
Tom's Team Ltd.
