fitting fascia UPVC

21 May 2013
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United Kingdom
I am about to replace some wood fascia boards but I want to overclad with upvc as we live in a area prone to constant winds and this tends to weather woodern boards.

I have read that some upvc fascia can warp/distort under weather conditions i.e. heat/cold, is there a minimun thickness I should use, reason I ask is that if I use thick upvc it will move the guttering out maybe to far away from the roof tiles allowing rain to be blown inwards.

So would like to keep the upvc as thin as will be pracital, what is the best way to secure the upvc to the woodern fascia board bearing in mind that the guttering supports will do some of the job just concerned about any warp/distorting of the upvc.

The fascia has a 7 inch drop so not so large, what would be the best way to secure the upvc i.e. pining ?
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Personally I'd replace the old if it's started to rot, not overclad with the thin stuff.
9mm capping fascia, fully supported on a timber backing (the old fascia) and double nailed every 600mm (maximum) will be fine

Use polytop stainless steel nails at least 40mm long

Any soft rotten existing fascia should be cut out and replaced
Hi, I have been installing Upvc fascias for over 15 years, personally I would remove the old boards and replace with load-bearing new ones.

If you cap over the existing then you may reduce the tile overhang, potentially have issues with window openers (they hit sometimes hit the fascia preventing the window from opening fully) and create a "step" between your roofline and that of your neighbours (if semi detached/terraced). There is also the risk of any rot from spreading as a cap fascia causes the timber behind to sweat.

I created this webpage, the photos illustrate a common problem, even with thin fascias -

I use replacement 18mm Floplast secured to the end rafters with 65mm stainless steel nails Polytop nails.

If you wanted to go ahead with the capping of the fascias then you will need 9mm or 10mm cap boards, they are usually secured with 40mm nails, two nails every 400mm. I would consider using 50mm nails and pre-drilling a pilot hole into the fascia. (no need for pilot hole with small 30 or 40mm nails) I have seen some plastic boards that are about 1 or 2mm thick but to be honest - they just warp, regardless of how many fixings are used. Also the nails tend to pop through the thin plastic and it comes away from the roof.

If you are securing guttering brackets to the fascias then I would consider using 40mm screws for each gutter bracket so they wind through the cap fascia and into the old fascia - this should provide a more secure fix.

For cap fascias I think it's absolutely essential to install an eaves tray, as this will help prevent issues caused by reduced tile overhang, it will prevent water from blowing in during windy weather. Please see - (yeah that's my pic too)
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THANKS for your replys, yes the origional fascia boards are worn and have a small amount of rot, this seems to be on the W S/W facing side of the property where 90% of the wind/rain come from.

So reading the general theme seems to be to take out the origional wood fascia board where there are signs of rot/damage, I will do this as its no good to just cover the rot as it will come back to cause problems in time this is what I am trying to avoid.

Maybe a bit more time & effort now will pay off later, about the over hang of the tiles/gutter this I must check carefully to see if I were to fit new wood fascia then put upvc over I need to know the overhang of the tiles as maybe I will not then put new wood fascia just put upvc direct to the rafters or what ever the origional woodern fascia is secured to.

Thanks for the pictures Danielroofer, as the saying goes "a picture paints a thousand words" what you are saying is well illustrated in the photo's.
Hi, I have been installing Upvc fascias for over 15 years, etc

Nice post and blog

I don't agree with the sweating comment (the timber stabilises) but definitely agree with the need for plastic eaves trays with this type of work - very few people do this or mention it to their customers

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