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Retro-fitting trickle vents to upvc windows

My first floor flat is suffering from condensation on the uPVC windows and there's now damp signs appearing on the walls too. I've read that fitting trickle vents to the window frames should solve the issue. I think this is a easier solution than fitting air bricks to each room. Appreciate any feedback? Thanks

3 Answers from MyBuilder Window & Door Fitters

Best Answer

Simple enough job to retro fit trickle vents to window heads,
Window manufacturers will stock them in colour to suit.
Basically drilling holes in head of frame couple of screws to fix


Answered 22nd Feb 2011

it is not a easy job to retrospectively fit trickle vents and it is unlikely to solve your condensation problem , assuming the condensation is not in-between the sealed unit (which would mean it is blown and need replacing).
the condensation is caused because the out side temperature and the inside temperature differ and this causes the moisture in the air to form on your window as condensation
the better rated sealed unit you have the less condensation you will get if you have a A rated sealed unit which would comprise of 2 pieces of ionised /k glass a warm edge spacer and argon gas you would not get condensation ,from the sound of it your windows have been in for some time and will probably have a c,d,e,or f rating
the only way you are going to solve your problem is to change your sealed units and windows to A rated

Kind Regards
Tim Harris
MD oak leaf windows ltd


Answered 24th Feb 2011

Dear aa40.
In general terms, trickle ventilation will provide some assistance with the problem if the condensation is forming on the inside of the sealed double glazed unit and not in between the pains of glass. However, I would be more concerned with respect to the source of moisture assuming that the room it is not a bathroom, WC or Kitchen. There are many causes for raised moisture levels in the home and more often than not is due to poor or faulty ventilation and or extraction somewhere in the home or could signify a building envelope failure or leaking pipes, gutters ect. You should investigate any or all possible sources first and reduce or eliminate where ever possible.

Without seeing your windows, I would say that it is highly unlikely that you could successfully retrospectively install trickle vents into your window ( due to drainage and damping) but you may be able to install new “night latches” instead that opens the window ever so slightly and can be locked to provide security. Failing that, installing airbricks is not a huge task but I would recommend that any penetrations through the exterior wall is cored ( round hole is easier to form) and a proper cavity sleeve is installed ( this may need to be fire rated). You may need to seek permission from the freehold owner to carry out this task as you have said your dwelling is a flat.

Hope this is of some assistance. Please feel free to contact me if you need any further assistance.
Kind regards, Kieran Gannon MCIOB.


Answered 23rd Feb 2011

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