Age and type of house
A king post was cut to let a stair through and a steel flitch is bolted beside the cut. What calculation of that flitch was not in the survey?
No calculation of that steel flitch was in the survey. A king post was cut so a stair could pass, and a flitch plate is bolted beside the cut. The inspection can describe the cut timber and the steel that was seen: the plate, the bolts, and where it sits against the post. It cannot say the plate is the right size, the bolts are the right number, or the stair loads are carried. That calculation was not attached and was not done on this visit. Approved Document A is structural guidance. It is not a certificate the survey has issued for the flitch.
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?
A king post is the central upright of a truss, working with the tie. Cutting it for a stair breaks that line. A flitch is a steel plate fixed beside the timber to help the remaining wood. Bolts show that someone fastened a plate there. They do not show the design that chose the plate. Without a calculation, the survey has a description, not a check of section or load. Use of the stair is not arithmetic. Approved Document A does not turn the bolts into a design.
Ask the solicitor for any engineer's calculation or building-control paper for the cut king post and the flitch. If none is produced, a structural engineer can assess the plate as a separate instruction. Tell them the survey describes a cut post and a bolted flitch, and that no calculation was in the report. Approved Document A has not been applied as a sign-off. Do not treat the stair as approved because it is usable, and do not remove the flitch, or add to it, on the authority of this note.
What should you ask your surveyor?
- What of the king post was cut, and where is the flitch bolted?
- Was any calculation of that flitch included in the survey?
- Have you left the size and the bolts unchecked against a design?
What are the typical next steps?
- Describe the cut post and the flitch, not a calculation you do not have.
- Ask the solicitor for any design for the stair alteration.
- Do not read Approved Document A as approval of the plate.
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
If the bolts look new, has the flitch been designed?
No. New bolts show recent fastening, not a calculation. No calculation of the flitch was in the survey. Approved Document A is structural guidance and has not been issued here as a certificate. The plate remains undesigned in this report, however fresh the bolts look.
Does a stair that feels solid replace the missing calculation?
No. A solid feel underfoot is not a design check. The survey did not calculate the flitch, and Approved Document A is not that calculation. How the cut king post and the plate share load is still unshown. Use of the stair does not fill the gap.