Age and type of house
The survey records a slight sag in a steel lintel over a wide 1930s window. What has been established?
Only that the surveyor saw a slight sag in that one lintel: an observation, not a measured deflection and not a calculation of the wall above. It is also more than a note that a lintel exists. Ask how the sag was judged, whether the masonry over it is cracked, and whether they want an engineer to look.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Naming the material is a different sentence from describing a sag. Here the report has already gone further: someone saw the steel dip. You still do not have a millimetre figure unless they wrote one, and you should not invent one. A wide opening is where a small dip shows. The brick or the render above may be cracked, or it may not. Those are separate observations the survey should keep apart.
A home survey does not open the lintel or test the steel. Slight sag is not a prediction that the wall will fall, and it is not a clearance either. If the window sticks, or a crack runs off the end of the lintel, say so when you instruct anyone else. An engineer, if you need one, is a new instruction. Do not ask a window fitter to decide the wall.
What should you ask your surveyor?
- How did you judge the sag: by eye, or with a straight edge?
- Is the masonry above cracked, or is the sag the only comment?
- Are you recommending an engineer, or only recording what you saw?
What are the typical next steps?
- Do not add a deflection limit the report did not use.
- Point a structural engineer at this opening if you need more than the observation.
- Do not replace the window and assume the lintel was included.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Is every 1930s lintel defective because it is steel?
No. The material is not the defect. A sag the surveyor saw is the comment to follow up.
Does a soldier course of bricks prove this lintel is sound?
No. Bricks on end can hide steel or sit without it. Ask what was actually seen over this opening.