Loft Project

[Phill123]

Hello All,

Thought I would post about some recent works in my loft. I recently noticed a few of the top floor ceilings were sagging in specific spots & some signs of woodworm showing in our recently purchased property. After inspection of the loft space it was clear that there were a few issues:

-Horrible glass insulation, which is completely insufficient in places (Depth)
-The smell is also very strong due to a wide range of faeces throughout the loft space.
-The roof appears to have been re-felted/slated in the past 30/40 years. And all the old lime mortar, along with anything and everything is buried under the insulation. In some areas you can't actually see the joists and this correlates with issues in the underneath rooms.
-There is also woodworm everywhere. But I suppose particularly the lath (in the centre run) & all of the rafters.

I will get some more pictures of the progress updated too. And currently pricing up some thermafleece.
What would everyone's recommendation be with the woodworm. Treat? Or would removal of the issue and installation of the correct product rectify the problem?


Thanks
Phil

 

[LadyArowana]

Do you have bats? They are protected and you aren’t supposed to harm roosting sites. Being caught could be expensive.

 

[MatthewC]

I'd suggest that your first job should be to get rid of the ghastly modern insulation (and I know that will be a horrible job!) and make sure the loft is ventilated. If you then leave it through next summer, by then the moisture content in the woodwork should have reduced to a low enough figure for all the woodworm to die. (I think it's 14% minimum they need.)

Then do woodwork repairs as required, and fit Thermafleece (or equivalent other sheepswool product) in an adequate thickness (about a foot). That is breathable and so will allow any residual moisture to disappear. It is also much nicer to work with as there's no prickles, although you do need to learn how to cut it easily and neatly. I installed it in 2011 and have been very happy with it. (NB I also learned to use a mask anyway in an old attic, after getting a nasty cough/tickle twice.)

I agree with the Hon Lady re bats - there were some major building company just last week who I heard had been fined £600,000 for ignoring the advice given and annihilating a colony of one of the rarer species of bat. I guess they will just add £1,000 to the price of each house...

 

[Feltwell]

Yes, what's generated the guano would be my first concern, if bats then professional advice definitely required. No need to spray chemicals around for woodworm, if the moisture content of the wood is low enough they cannot survive as Matthew says - "Woodworm" is a catch all term so I'm presuming you mean Common Furniture Beetle. The holes you see are flight holes where they've left the timber, so it can take a while to determine if it's active or not - you need to clean up then look for fresh signs of "frass", the dust they produce. Your woodworm could date back to an old, dead infestation when the roof was in a bad condition. Pretty much every old house has had furniture beetle somewhere at some point!

With that in mind don't assume that it's the insulation that is the issue - checking the roof is watertight, particularly in areas like lead flashing and chimney flaunching, should be done. The roof space needs to be adequately ventilated to stop condensation, it may be that you had moist warm air coming up from the house through a badly fitted loft hatch for example. It may be that you need to fit some air bricks in gable ends, it may be that your insulation is stopping all ventilation at the eaves if it's badly fitted. You need ventilation above whatever insulation you have. From your picture it looks like you've got standard roofing felt under the tiles/slates, which is a shame as the modern breathable roofing membranes are far better. Not a problem though so long as you have sufficient other means of ventilation.

Spraying chemicals around is a bad idea for many reasons. We had an expert who used to post on here (Matt Green - haven't seen him in a while) - I remember him saying that I had one of the very few examples of where chemicals are required, my cellar steps have furniture beetle and being in a damp cellar (as pretty much all are) drying it out isn't possible in a sustainable fashion - but your roof space should be dry enough if everything is right.

 

[YorkshireCottage]

Do you have bats? They are protected and you aren’t supposed to harm roosting sites. Being caught could be expensive.

I didn't think bats occupy felted roof space. I'm not an expert though, so don't hold me to it.

 

[LadyArowana]

I showed your picture to my very competent builder and he thought highly likely you have bats, because they often hang from the centre. We absolutely don’t have any bats at our place ( confirmed by multiple visits by an ecologist prior to our roof replacement- done under LBC ) but the builder has done many projects where they are found and “mitigation” measures are needed to ensure the roosting site isn’t harmed. In one situation similar to yours he loose laid something over the top of the insulation to stop guano contamination or it leaking to the ceiling below, the householder could then remove and replace that covering periodically as necessary.

 

[Phill123]

We haven't seen or heard any bats in the past 9 months, but reading up on BCT that doesn't necessary mean they won return to a roosting site. However I will take onboard comments regarding professional advice before tackling any potential issues up their.

Thank you for the advice.

 

[Flyfisher]

Yes, best to leave these things to the professionals, they know what they're doing, especially when spending someone else's money:
https://www.bbc.co.uk/news/uk-england-34605886

 

[LadyArowana]

I didn't think bats occupy felted roof space. I'm not an expert though, so don't hold me to it.

Our “Bat man” ( who never found any bats ) said that some of the loosely woven types of linings in roofs can entangle the bats little claws and then they can’t free themselves and they die. We had to install 2 “bat slates” ( essentially lead pockets on the outside of the roof ) + 2 “bat boxes” and when he came back to certify our mitigation measures he was specifically checking they couldn’t get stuck. It seems a shame now that we have nice accommodations for bats that there actually aren’t any, maybe a Listed Building Application to put one of these out on the roof as a welcome [https://www.amazon.co.uk/Decorativ...8057104&sprefix=neon+bat+,aps,171&sr=8-5/url]

 

[Flyfisher]

Over the past decade or so I’ve made four successful LBC applications, three of which involved work to our roofs and two of which involved complete stripping of all tiles. None of the applications or conditions of approval required a bat survey to be carried out.

 

[LadyArowana]

Over the past decade or so I’ve made four successful LBC applications, three of which involved work to our roofs and two of which involved complete stripping of all tiles. None of the applications or conditions of approval required a bat survey to be carried out.

Our architects were very surprised that the CO made all the fuss she did about bats, they had done one or two other similar projects in the same road, which is only 36 or so houses, and it had never been an issue. We thought after initial visit found zero actual bats and zero evidence of bats ever being there that it would be plain sailing. But no. Still had to do all the things to be bat friendly. Even the consultant ecologists was clearly only “ticking boxes” with little expectation that bats would be moving in.

 

[Flyfisher]

So inconsistent across the country!

For one LBC application I needed some architectural design drawings and I used a friend in Herfordshire, where we used to live. He suggested that not only would we need a bat survey but that we might also need a newt survey because of our ponds (which are about 75m from the house!) and that even if not we'd almost certainly need to protect the building site with 'newt-proof' fencing because of the 'close proximity' to water, based on his experience of some projects in Hertford. I explained that these issues hadn't cropped up in my previous applications so I didn't raise them and neither did our CO or the council.

Fortunately, I was making the formal application myself but if the architect had managed things I guess he would have raised the issue himself, perhaps even persuading me to have a bat survey before application so that any implications could be addressed in the application. I guess the professionals are more attuned to such things and are keen to avoid any potential liabilities - after all, they don't have to pay for such surveys or any implications arising.