Insulation

Aluminum Foil in Loft placed on top of boards

Anonymous user 01/03/2024 - 3.00 PM

Hi, I currently have 100mm of standard insulation wool in my loft which is boarded and am getting condensation that is appearing on the felt in the coldest days when our heating is on. As a low cost solution can I put aluminium foil on top of the boards and then put an additional layer of insulation on top of that? When placed in this way will the aluminium foil act as a vapour barrier and do the job that it was designed to do, e.g reflect warm air back into the house and help stop condensation/warm air from getting in? I think the ideal solution would be to lift up the boards, put the foil underneath the existing insulation, then put that back on top and then top-up with another layer, then raise & put the boards down, if that is correct will putting the foil on top of the boards work or will it possibly cause any issues in the air-flow and and heat movement in the loft? Many Thanks for any advice, I really appreciate it