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Lean-to polycarbonate greenhouse against the house


I am planning to build a lean-to greenhouse on the southwest corner of my house (on the west wall). The house is cavity brick wall with insulation installed. I am wondering whether there will be humidity/mold/moss/rot or any other degrading issues in the greenhouse or the house itself caused by leaning the greenhouse against the house? Are there any recommendations on leaving a gap of air between or inserting some sort of membrane/insulation between house and the greenhouse? Or is it ok to leave the brick wall exposed to the inside of the greenhouse?

thank you very much for any advice or suggestion?



  • wild edgeswild edges The north west of south east WalesPosts: 6,203
    The brick will be fine as you will need to keep the greenhouse ventilated to prevent the problems that humidity etc can cause (I'm assuming it's not a tropical humid greehouse?). Make sure you aren't affecting the damp proof course in any way though. Keep the greenhouse floor level 6" below the DPC and make sure the frame isn't allowing water to track up over the DPC where it attaches to the wall.

  • Nanny BeachNanny Beach Posts: 5,726
    We have a lean to greenhouse, on the side of our bungalow, its the only one I heat in winter, with one of those tubular heater, not too expensive to run,and is the smallest greenhouse, we have, We are also cavity wall  and insulation, never been any problems with moss,rot,mould,humidity or anything else. No air gaps or membranes of any kind, and just the normal brick wall left.
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