Should replacement uPVC windows & doors be foamed?

Discussion in 'Other Trades Talk' started by Mrgreen1234, Mar 23, 2021.

  1. Mrgreen1234

    Mrgreen1234 New Member

    Hi all, about 18 months ago I had about 10 windows and a door replaced by a fensa registered installer.
    I had some water ingression on a corner so did some investigation.
    I found that:
    2. NONE OF THE WINDOWS HAVE BEEN FOAMED (there is only a bead of silicone on the outside between render and frame)
    Looking from the inside I can see a gap of about 10mm between frame & block work.

    MY QUESTION IS: Are points 1&2 requirements and essential for a Fensa installation?

    The installer is coming to site to "address my perceived problems" and I know they will say foaming is not a requirement.

    Many thanks in advance

    Read more:
  2. Teki

    Teki Screwfix Select

    Expanding foam isn't a requirement but often ensures an airtight seal. If the external silicone has been applied properly, you should have no water ingress.

    Give an opportunity for the installer to rectify the issue otherwise report to Fensa.

    Is it a national company?

    Can you post some photos of the sill upstands and ends?
  3. Mrgreen1234

    Mrgreen1234 New Member

    Hi Teki,
    Thanks for your reply. I have lots of images which I will upload/link this evening.
  4. Mrgreen1234

    Mrgreen1234 New Member

    A bit more info on the build up:
    We had the replacement of 10x upvc windows and 1x upvc door completed by a Fensa registered installer and were pleased with the installation. As we had ongoing renovation works planned throughout the house it was agreed that windows, external sills and internal plastic sills were to be fitted but internal making good of reveals was to be done by ourselves.

    (We have had issues on a kitchen door with ingression on the sills corners)

    Since the original install our 2 x bathroom windows had internal plastic sills and plastic strips on the reveals. We are currently in the process of having our bathroom re-fitted. This involved removing the plastic internal sills and having the entire room re-plastered. After a rainy and windy night we noticed moisture appearing on one of the reveals, this ingress would not have been revealed if the plastic non porous sill was still in situ. Please note that there is no bridging of the cavity due to plasterboard, bonding or muck.
    I cut out the area of wet plasterboard and sent image to a third party professional window fitter for some initial advice and he said "it looks like he hasn't troughed the end of the sills properly"

    I contacted the original installer and he came along with a roll of damp proof membrane saying " your outer cavity wall will be wet anyway so this will stop any moisture transferring to the inside when I put this between the outer and inner wall".

    My reply was "no, my cavities should not be wet as I have loose fill cavity insulation, and fitting the DPM will just be a sticking plaster over a poorly sealed window. The reason I had all my windows replaced was to stop water ingression". The external wall is rendered and painted.

    I asked the fitter if he had ran a silicone bead between the element and sill upstand on installation. He replied "Yes I have done that but if there is a small gap or break water will get in".

    The installer then made the following attempt at rectification:

    • Squirted silicone into the corners of the reveal
    • Cut out a strip of plasterboard along the back edge of each window and filled with silicone to provide a barrier
    • Squirted silicone from the outside into the corners of the drainage channels (on a new installation I do not think this is acceptable and looks shoddy)
    Since the installers remedial attempt water is still entering the cavity via the sill edge.

    I have also noticed a lack of bedding or a void beneath the outer sill. (If you look closely you can see the silicone bead applied to the outside.)

    All of the above has seriously raised my concerns. So I decided to remove a smaller window elsewhere (which I know will affect any warranty but I am willing to take the hit on this).
    I found that no silicone had been applied to the sill upstand, as per the manufacturers guide at all. The two blobs of silicone are also the installers remedial attempt.

    Following my research I believe the following issues exist:
    • Nonexistent PU backing or foam applied to window frames
    • Void above living room window causing howling draughts and transfer of noise
    • Nonexistent bedding and voids beneath sills
    • Nonexistent fixing to heads of various frames
    • Fixings located within 150mm of corners and transoms
    • Sill up-stand and ends not siliconed at all throughout entire installation
    • Drainage paths partially blocked by your previous attempts at rectification
    • Insufficient external sill projection on various windows
    • No use of packers between frames and blockwork

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