Architrave around UPVC Sash Windows


7 May 2020
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United Kingdom
I am in the process of a house refurbishment and had a company fit UPVC Sash Windows, the finishing off was to be completed by others - my builder agreed that this could be undertaken by them. The old windows were wooden and too far gone to be saved so the box was removed etc hence quite a bit of making good.

I have inspected the "making good" and stopped any further work and spoke to my builder. He advised that the making good is acceptable and they have done nothing wrong - see attached pics.

I see a number of problems;

1. Architrave is to small - it does not meet the picture rail. Builder advised that wider architrave is not readily available. It is standard practise to have smaller architrave.

2. I understood that architrave was to butt up against the side of the bottom bar. Builder advised this is incorrect as architrave trim has to be put over the UPVC frame (as shown in pics) in case of natural movement.

3. Builder advised that wood is generally not used to trim UPVC Sash as wood and PVC do not go together - it is difficult to blend in.

4.The wood architrave has in part been attached directly to the UPVC sash frame using Mitre Fast Activator. I checked with Everbuild and they advise that this product would permanently stain the UPVC (PVCu Acti-Spray would have not). Builder advised Mitre Fast Activator is acceptable to use.

I do not believe what the builder is telling me and I have a further meeting planned to discuss this matter. I would be grateful for any guidance / advise on fitting architrave to UPVC Sash Windows so I am bit more clued up beforehand.


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It’s shocking I hope you haven’t paid him yet.Your architrave is far to small. You could do to speak with the builder and ask him to employ a joiner to finish off the window. I’m interested to find out what the original specification for the job was.
The windows were discussed before any work commenced and it was written that windows were to be made good. Now I understand "made good" is to repair and bring back to its original condition. The builder never raised any concerns before or during the work until I requested it stop. I cannot believe that he thinks there is nothing wrong.

I have an appointment this weekend with a Joiner to discuss the architrave, however, I am very concerned about any damage to the UPVC frames caused by the glue used.
Ok understand that you’re concerned about the potential damage. 1) check frames haven’t been compromised and screwed into. 2) solvent glue can be removed from frames . 3) Your joiner should know how to marry up to the upvc line including a plastic or wooden trim. 4) Good luck.
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Unfortunately it is hard to tell exactly what is going on with the detailing.

However, the attempt to scribe over the upvc ovolo is a bodge and incorrect.
More thought should have been put into that to ensure the profiles of the window and the architrave did not clash.
possible a timber trim the same thickness as the ovolo mould should have been scribed to the ovolo and fitted first, then the architrave fitted after.

In regards to the architrave itself -its one of those instances where a lack of specification for the work has meant your expectations didnt match what was done. I learnt from many years of dealing with these details is that the only safe way, is to discuss all details with the customer -otherwise they are left in the difficult position of not having the opportunity to make the decision before the work is done not be forced to accept it after.

Your employed the builder to trim up the windows and finish -but he has hasnt: there is a gap between picture rail and architrave. So the job is not complete. If he couldnt get any other architrave, he should have explained to you what he could do and let you decide.

When replacing period joinery, I personally would always offer to fit identical mouldings as the original where they are a period feature, or I would choose the nearest to match that style and period.

sadly you shouldve employed a skilled site chippie to do the job.

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