Outbuildings and conservatories
Polycarbonate sheets on a conservatory are opaque and crazed. What has aged, the sheets, and what frame or foundation has that haze not condemned?
What has aged is the polycarbonate sheets. They are opaque and crazed, which is how that plastic fails in sunlight. The haze has not condemned the frame, and it has not condemned the foundation. The survey has seen the sheets. It has not said the bars, the base or the ground under the conservatory have failed because the plastic has gone milky. Opacity is a sheet failure, not a finding that the conservatory structure has moved.
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?
Polycarbonate loses clarity when its surface breaks down under ultraviolet light. Crazing and opacity are sheet defects. The aluminium or timber frame can be sound while the sheets are not, and a foundation is a different structure again. The survey can describe the roof plastic it looked at. It did not test the frame joints for a cause connected to the haze, and it did not inspect foundations. A tired sheet is a reason to think about new sheets, not a diagnosis of the conservatory as a whole.
If you want the roof clear again, ask a conservatory contractor about replacing the sheets, and keep that as a sheet job unless they find something else. Tell the solicitor the survey has not condemned the frame or the base. Do not read opacity as proof of movement. The plastic has aged. The rest of the conservatory was not written off with it.
What should you ask your surveyor?
- Are the opaque, crazed parts the polycarbonate sheets?
- Has the haze been kept from condemning the frame?
- Has the foundation been left out of this sheet note?
What are the typical next steps?
- Treat the haze as aged polycarbonate sheets.
- Ask a contractor about the sheets if you want them replaced.
- Do not condemn the frame or the foundation from the haze.
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 a bar is bent, did the sheets cause it?
Not on this note. Bent metal, if you see it, is a frame question of its own. The survey has not blamed the frame for the opaque sheets, and it has not said the haze proves the bar has failed. Sheets and bars are separate.
Does crazed plastic mean the base has settled?
No. Crazing is surface breakdown of the sheet. Settlement would be movement of the base, which this haze has not shown. The survey has not condemned the foundation because the polycarbonate has aged. The base was not the thing that crazed.