Weight of roof on conservatorybwalls

Hello You've probably had the answers already, but just encase, I thought I may be able to assist (30 years in conservatory and extension surveying) so I am fully aware of the building regulations and structural calculations where required (I am not a structural engineer but I have constant access to one through my business). I can assure you that these panels would not cause an issue with an issue of added weight, HOWEVER............And this part is massively important so pay close attention. If you have a relatively new conservatory (4 years or younger) then Thermotec panels or even Greenspace panels (there are many others) are a perfect way to insulate a cold conservatory or even help with overheating in the summer months, BUT..... and it's a big but! if your conservatory is old it's very likely that the external roof bar caps and the rubber roof seals have become brittle due to long term exposure to UV rays (the sun) which means that this type of roof upgrade is a MASSIV NO NO. it's highly likely that removing the existing roof bar caps otherwise known as rafter caps whilst trying to remove the existing polycarbonate or glass units will cause the rafter caps to break and disintegrate, this will mean that you will need new rafter caps, easy right..... WRONG, if you have an old conservatory it's highly unlikely that these rafter caps are still available to purchase, the double glazing and conservatory industry has been and continues to be a fast moving innovative industry with new products coming to market every five years whilst older products are phased out, so if you are unable to get your hands on new rafter caps you will then be in the position of having to purchase a new roof structure, ADDITIONALLY, and this one is equally as big, the panel insulation companies have a caveat in EVERY contract, if your roof leaks "it's not the panels fault" ITS YOUR EXISTING ROOF STRUCTURE!!! My personal opinion is that these roof solutions should be barred from any conservatory that is older than 4 years. I hope this helps, if you think I can help any further, please feel free to reach out. Best regards Brandon

Hi, This is one of those situations where there isn't a simple "maximum weight" figure that applies to every conservatory. The ability of a conservatory frame to support a roof isn't determined solely by the weight sitting on top of it. It depends on several factors including the frame design, mullion spacing, reinforcement within the uPVC sections, roof span, box gutter design, wind loading, and how the loads are transferred down into the foundations. Looking at your figures, a roof weight of around 400kg spread across a conservatory measuring 7.2m x 3.5m doesn't immediately sound excessive, particularly as the structure has been standing for around 10 years without any signs of movement, distortion, cracking, dropped corners, or problems with doors and windows operating correctly. What would concern me more than the dead load itself is whether the original structure was designed and reinforced to carry that particular roof system. Many conservatories were originally designed for lightweight glass or polycarbonate roofs, and problems can sometimes arise when a heavier solid roof is installed later without checking the original frame specification. In practice, when I survey these types of projects, I look for evidence rather than relying purely on calculations. Signs such as bowed frames, sagging box gutters, cracked seals, movement at corner posts, separation at joints, or difficulty opening doors and windows will often tell you more about the adequacy of the structure than a theoretical loading figure. The fact that Building Control have said you may require steelwork suggests they are being cautious rather than identifying a specific failure. Without structural calculations or details of the original reinforcement within the frames, it can be difficult for anyone to give a definitive answer from a visual inspection alone. Personally, if the conservatory has been carrying the roof successfully for a decade with no signs of distress, that is certainly a positive indicator. Structures generally don't wait ten years before suddenly objecting to a load they have been supporting all along. If you can provide details of when the Thermotec roof was installed, whether it replaced an existing roof, and some photographs of the frames, box gutter and corner posts, I may be able to offer a more informed opinion. Kind regards, Colin Prembuild Midlands Ltd