New fascias and Soffits - to Overclad existing or Replace?

12 Jan 2009
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United Kingdom
I have had quotes from double glazing firms to replace some windows in my house, and hope to have the existing (timber plus low asbestos content board) undercloaking to my roof replaced with white uPVC soffits and fascias at the same time.

I have had quotes to rip out and replace the soffits and guttering, and also to overclad, come out at the same price - so expense is not going to be an issue.

The advice to overclad is because it will be a quicker job, will need a ladder rather than scaffolding, and will be superior to the alternative as the bottom tiles of the roof will not need to be replaced. Apparently when the existing undercloaking/soffits are removed and replaced with uPVC, over time the plastic uPVC warps and bends, allowing gaps for water penetration into the roof space.

The advice I've received to rip out the existing undercloaking/soffits and replace from scratch is because with overcladding what's remaining underneath will rot over time and cause condensation, eventually damaging the roof timbers.

Can anyone advise me which advice I've received is the best option?

Thanks ;)
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The advice you've received is bad. Not just in terms of the merits of each, but the job content and how it will be done

Overcladding, done properly will give no problems

You simply don't get water penetration from a soffit

You don't get condensation between overclad fascia or soffit.

Timber does not rot unless there is a persistent roof leak. It wont rot just by being there. But, any existing rotten timber should be cut out and replaced.

However, there is potential for replacement plastic to warp, twist and bow if inadequately fixed or supported, so its best to overclad.

BTW, have the quotes allowed for licenced removal of the asbestos sheet? You will be responsible for it if it gets dumped around the corner
Hi Woody

The quote to remove and replace the existing is in view of it's asbesos content, however low, and they didn't seem phased by the fact the undercloaking is asbestos board - I guess because it is a familiar material. The salesman did mention that there are requirements for asbestos to be safely disposed and confimed the quote would reflect the overal price of removing and replacing. The mess and chance of fragments falling into the garden as a result of removal is something that concerned me, but having to ensure they adhere to disposal regulations and do things legally is something extra I didn't factor into the job at all.

Aesthetically with overcladding, the existing soffits are large and jut out quite far so the overclad may exaggerate this - I think they said around 8-10 inches wide.
You wont notice any difference from down on the ground!

With regards the asbestos sheet, any contractor, whether licensed or not, will have to remove the sheets in accordance with the Hazardous Waste Disposal Regulations.

This may require an enclosed skip or similar, disposal to a site licensed to receive asbestos waste - and full transfer documentation.

So make sure that quotes include the above and compare like-for-like.

TBH, I've never known any of the companies doing these types of private jobs to remove asbestos sheet legally. But you may want to ensure that it is disposed of properly and safely to an approved tip - and not dumped in a lay-by or put out in a black sack for the binmen
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on an average roof a 9" soffit is fairly typical and aesthetically appropriate, or...... just looks right. :LOL:
What has amazed me is that the price for the replacement boards and the cover boards have been the same! it should cost more to used replacement upvc boards that cover.
Personally i prefer using cover boards because its quicker and cleaner but if im honest i would use replacement boards on my own house!
Hope this helps
The quotes for the same price were from 2 different glazing firms. Thanks for all the advice here, I think I will overclad the existing as it is the most straightforward option, especially if there are no indications associated with the timber soffits suffering from condensation inside the cladding.
Windows companies have very little knowledge of this product and thats why you have so many varying quotes or in this case one company trying to rip you off for overclad or the other not understanding that scaffolding is required for full replacement.

However, to me it seems that lack of knowledge has been the order of the day with the guys you have seen (but thats what i would expect from a window installer).

Overclad - the job is cleaner and by far more aesthetically pleasing, because of the Tongue and Groove effect on the underside (soffit) providing it is fitted with starter trim that is. There is absolutely no evidence that the timer rots underneath and with my company the same guarantee applies for Cover or Replacement.

Full Replacement - If the job is fitted correctly with New timber noggins to re-inforce the soffit structure and the materials are of decent quality then onmce again there is absolutely no evidence of Warping or Bending boards (we did 175 houses 9 years ago for Bham city council and they are still perfect) You do get extra ventalation with replacement soffit, however this can be counter acted with Soffit vents on the over clad drill cored straight through.

The only thing that Full replacement provides for anyone is the fact that it has been replaced so they can squash the myth of timbers rotting underneath and the fact that they had far to much money to spend initially (unless the timbers were to rotton).

Incidently - If the timber rots underneath the UPVC fascia then should we be having UPVC at all, after all the Replacement Fascia fits to the TIMBER rafters, the most important part of your roof. Just a thought......
They are using thin plastic if they warp! I replaced fascias on my house last year with approx 16mm thick plastic. That stuff doesn't warp! Im glad I took that route as some timbers were rotting so gave opportunity to replace. I also removed the asbestos sheets

To do a proper job with thick plastic, scaffolding will make life much easier for the workmen. I wouldn't like to have done mine off ladders and if I had done I wouldn't have been up there long!

I would go into finer details of what guys who will be stripping it all off are using.
I have been installing Upvc fascia and soffit boards for 12 years, I have never capped over existing boards. I always remove the old. I follow guidelines for the removal of asbestos and always have the transportation license sorted. I use a licensed disposal yard. I would reccomend removing the asbestos soffits and timber fascia prior to fitting the new UPvc products. I strongly disagree with anyone who thinks capping over is a better job than replacing. If you are in doubt why not contact the UPvc manufacturers and ask them what is best. or perhaps pick ten companies and give them all a call asking them all the same question- what is best cap or replace?

As I stated I have never capped in 12 years - for a reason its a rubbish "cut a big big corner" job. My wife also works at a UPvc suppliers (how we met) she is also against capping over. She told me she knows when she is serving cowboys because they always buy thin capping boards. No reputable company would ever say capping is better than replacing.

I have seen many capped jobs and in my opinion they all look rubbish and I have seen the following problems:

The new gutter is further away from the house - potential for the water to run behind the guttering.

I had to remove one capped job because the window openers were hitting the new fascia and one of these windows was a fire escape window! imagine that - a fire in the house and the only escape is a window that wont open fully!!!

Contrary to what other people have written here I have replaced a capping job and seen a lot of rot in the fascia, wether that rot was present when it was capped I cant say, but it was a lot of rot - more than usual

Overhang from verges is reduced - potential for water to run behind fascia.

The cost of removing and disposing of asbestos soffits is not as expensive as you think. A transportation license costs £85.00 and around £150 for the disposal. Although strict guidlines must be followed for the removal of these boards a license is not required so the labour charge should be the same or only slighty higher than removing a non asbestos board. It is worth remembering that the asbestos is contained within a cement board it is not loose dust.

How many homeowners have inadvertantly drilled holes into these asbestos boards, perhaps to fit an external light or to provide roof ventilation? the dust released this way is far far greater than simply sliding out the boards in accordance with the guidelines. You are at greater risk form your neighbour sanding down an asbestos board and trying to paint it - than paying a couple of hundred pounds extra and getting it removed.

I would rather live in a house that had no asbestos - wouldnt you?

Anyway who is to say that regulations might change in the future, perhaps trying to sell a house one day with asbestos could be a real issue? not now but maybe one day?

I would also like to know how these capping companies actually fix the new soffits to the old asbestos? you cant nail it because it will crack the asbestos, you cant drill and screw the asbestos becuaes of the dust released. I have only ever seen the soffit board held in place with a trim which itself with is held to the asbestos with mastic and glue - hardly a secure fix! Probably explains why so many capping jobs have to be re fitted.

Heres one of my photos * View media item 9816 not capping job*
Over boarding does avoid disturbing the tiles but I think you’re being fed some horse ****e to sway you towards a quick job & easy money; the relative cost of the materials is nothing, it’s the labour cost that bites but the job has to be done properly & a few hundred quid won’t do it properly. If you want a job that will last, replace with full section, 22mm UPVC boards, properly fixed & sort out the eves at the same time.

Over-boarding is nothing but a bodge, rather like papering over the cracks; the timber underneath will continue to rot at an even greater pace (presumably why your replacing) & then flimsy cover boards will just warp fall off!
upvc facing, soffit, and barges done properly with overboarding is perfectly acceptable practice!
so long as the woodwork the overcladding is getting fixed to is free from rot and is in good repair.
while doing refurb works for the local authority over the past couple of years ie re-roofing, rendering, and roof line replacement the overcladding was the prefered method, as opposed to ripping out perfectly sound facings,barges etc.
the works were done under the auspices of la architects and surveyors all of which were installed as per manufacturers specifications.
overcladding done properly looks and performs every bit as well as replacement products.

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