Our forums are intended to allow both structural engineers and non-structural engineers to discuss the matters which affect them, obtain help with any queries and act as a useful way in which to communicate.

For more information, please visit the I need help or frequently asked questions areas.

General Public forum for all website users to post comments or queries
Institution Forums > General > Sagging floor and cracks View modes: 
User avatar
Site User
Site User
Smithy123 - 12/12/2018 08:31:59
Sagging floor and cracks

We moved into a 1930s semi in May. Homebuyer survey carried out in February reported no problems with cracks etc.

The house has an extension which was built over 20 years ago. I've noticed, in the last two months, that the floor (which is LVT over concrete) has started to sag in one particular place in the kitchen, which is approximately where the extension is. It's dropped around 1cm at the lowest, and the sagging area is about 1 meter in width. The floor isn't sagging anywhere else that I can see. 

I'm aware that the long drought over the summer has resulted in a lot of subsidence claims, and I'm worried that this might be what it is. There are no cracks downstairs, but I have noticed vertical cracks going from the top of the door frames to ceilings in the doors upstairs and there are a few horizontal cracks in the old part of the house. One door has started sticking a bit (the one nearest the extension). 

They are all hairline cracks and none are diagonal, although there is one in the landing which goes around where the RSJ must be - where the old house meets the new house. The cracks inside the bedrooms have appeared since the summer.

There is also a vertical crack in the render outside where the old house meets the new house.

Does this sound like subsidence?

Thank you.

PLEASE NOTE: Users seeking advice on home improvements or adaptations should consult a structural engineer using our Building Confidence service, where you can locate a trustworthy professional near you and get the advice you need to ensure your works are safe and secure. No advice provided within the forum can be guaranteed by the Institution, neither can it be a substitute for a consultation on site.

It is important that before using any of the Institution forums, that you have read and understood our complete terms and conditions of use.

All of the pages on this website are the copyright © of The Institution of Structural Engineers.

The Institution of Structural Engineers, International HQ, 47-58 Bastwick Street, London, EC1V 3PS, United Kingdom
Tel: +44 (0)20 7235 4535 Fax: +44 (0)20 7235 4294
Registered with the Charity Commission for England and Wales No. 233392 and in Scotland No. SC038263
Follow us on: Twitter Facebook LinkedIn Youtube The Structural Engineer Jobs