Eaves and vents

What would happen to the building if the vents are closed off ?

My newly purchased home was built in the 70's hence has asbestos eaves. They are still in good condition so I am trying to encapsulate them by having another coat of paint on top as a preventative measure rather than removing them and risk creating more loose fiber.

The asbestos remover & encapsulator says painting can only be done on the visible side. The hidden side is still raw asbestos hence on a very strong windy day they could release fiber and send them into the home via the vents. Should I have these vents closed off ? Would this cause condensation or subsequent damage to the building over time as they were made for a reason and not just cosmetic ? And most importantly Can Asbestos Eaves Send Fibers Into The Home Through These Vents ?

The roof is flat and the house sits on a concrete slab. There are mutiple vents on the walls in the home. Please help!!! Photos attached.

The cost of encapsulating and closing off these vents will likely be the same as having all these asbestos eaves removed and replaced with new ones. I am terrified of the evil stuff being disturbed (by the professionals) and risk sending loose fiber on the property (on the ground or into the home through the vents etc) yet unsure what could happen to the building if these vents are closed off.

Thanks very much.

 

If you are handy and are going to repaint, just hack off the old interior plaster vents, patch the hole and re paint the rooms.

If you had the money you could just remove the asbestos, but it is no more likely to cause issue's than your neighbors eaves will

 

Hi Stoffo,

Thanks for the reply. I just have very little idea about building especially the structure hence don't want to risk blocking off areas that were made for a specific purpose.

I don't mind paying to have the asbestos removed if it is neccessary for health and safety reasons but just don't want to risk worsen the issue through lack of knowledge etc

I am not handy but can paint non-asbesos walls. I won't be touching any asbestos stuff. Will leave it to the professionals who know what they're doing.

However, blocking off those vent holes, won't this cause consendation or other structural issues since they were made for a purpose ?

Got freaked out after one asbestos remover/encapsulator told me the raw unpainted side of the eaves that is hidden under the roof could send fibers into the home through those vents on strong windy days.

However another told me not to worry about it as it is only an issue if the thing breaks. He says another coat of paint on the outside may not even neccesary as they were already painted some time ago, perhaps decades .... hence I just wanted another coat just for a peace of mind....

I think the fear of this evil stuff will likely kill me before the actual stuff does....lol

 

FYI,
Not sure if it was an actual fact or not, but back in the day the wife at home was more likely to get mesothelioma than the man/worker as she would shake out his work clothes prior to washing them

Am sure @Scott No Mates has some more info on this topic

 

yes i heard the same as well. But there isn't a great deal of details on the internet on how to reduce the exposure risk in the home.
Also worried about having them removed shortly before moving in could create more loose fiber on the property as well, on the ground/soil, deck etc but then again I have little knowledge on how it all works.

 

The internal vents on the walls are to stop carbon dioxide build up if you have a gas heater or a fireplace. If the house no longer has that due to having a split system then you can have them covered.

 

No issues with the unsealed side (probably has a good layer of dust covering the back of the boards).

Painting the eaves is fine just don't use a power sander & wear a mask.

As for the vents, also causes heat loss.

 

Thanks Westminster

The house does have a wood fire but I will never use it.

Is there a way to temporarily block these vents? I plan to sell this home eventually so should probably leave them there given the wood fire? May sound silly but would having tape or clear contact adhesive on them block out any potential dust/breeze that can go through?

 

Thank you Scott

such a relief to hear this

Regarding the unsealed eaves side, do they naturally deteriorate over time? The asbestos remover says asbestos eaves are the dangerous area ...compare to asbestos flue on top of roof (he says flue are really hard and won't crack unless alot of pressure is applied) ...does this mean asbestos eaves are more friable and easy to break ? Im thinking strong winds and storms etc .... how thick are these asbestos eaves generally?

 

The flue is riskier IMHO as the heat would make it deteriorate more than a protected sheet under the eaves.

4mm

No, it's a compressed matrix of ACM

 

Yes hence why I'd never use the wood fire... Not sure if the flue on top of roof is metal or asbestos yet but was keen to get rid of it....the asbestos remover said if asbestos they should be very very tough and reckons I should just leave it alone but remove the eaves.... not sure why he thinks the eaves' presence is more dangerous even when still in good condition.

4mm is very thin....so if left undisturbed they won't deteriorate with age at all regardless of time? The home was built in the 70's ...

 

Are your external vents above the eaves linings or below them in the brick work?

I ask, because my house has a flat roof like yours - and the vents were in the second top row of bricks. So the breeze goes in the external vent and straight throught to the internal plaster wall. So the breeze doesn’t pass over the eaves linings before going through the vents at all!

So, no need to worry - in this case there should be no connection with the vents.

(Separate comment: in asbestos cement sheet the percentage of asbestos is quite small and it is bonded in place by the cement. If you don’t break it or sand it or drill it, it should be no risk at all.)

If the underside of the eaves lining is already covered in a coat of paint, then more paint won’t add any more protection.

 

Thank you so much Joynz, I will do a closer look the next time I'm at the home. From the photos there doesn't seem to be any external vents in the brick work at all. From the photos I have, where the internal vents are positioned inside the home, there doesn't seem to be another visible vent directly behind it outside on the brick wall.

The roof is flat with eaves directly below followed by brick wall underneath. I was thinking if strong wind blows could dust from the eaves travel through the inside of the covered roof and wall structure then out through the vents ?

 

I had my eaves linings replaced in the end - a couple of the asbestos joining strips were degraded - but the main reason was that I wanted tradies to be able to drill into the eaves lining for power etc in future without me worrying about them wearing PPE etc.

Since I was having the shed cladding removed, I got the house eaves lining done at the same time..

 

Hi Joynz, I'd do the same... if i ever renovate the home then would ask the experts to remove as much asbestos as possible... but at the moment the eaves appear to be in sound condition and the place is already renovated so disturbing them would likely introduce more issues and send more fiber out than not. Alarms just went off when the asbestos remover warned me about the danger of having the eaves and dust going through the vents today.

Have just gone through the few photos available of the place and it appears there are no external vents directly behind the internal ones. Per the attached photo I've squared in green the internal vent visible inside. However in the corresponding external position directly behind, also squared in green, a vent is no where to be seen. Same to several other internal vents which I've got photos of. Is this unusual ? could the building have been designed to allow air to travel from inside the home to wall cavities through the internal vents with no equivalent external vents ? my knowledge in building is zero.

The eaves lining is above the brick work and appears to be above the internal vent in the photos but can't be sure just from the photos alone. Will carefully check this the next time I visit the home. I'll block off these vents regardless, thinking of the clear self adhesive contacts that I used to cover books back in the school days... not sure if this will work ...

 

Ok - they have probably been removed and bricked up then. That’s what I did with mine to stop drafts and cold winter air.

However, it’s quite common to plaster over vents on the inside in Melbourne - as it’s easier and much cheaper than bricking up the vents from the outside.

Don’t be too rough with the internal vents, as they are likely just made from plaster. They may even already be blocked.

And remember - they aren’t an asbestos risk as there aren’t any asbestos fibers coming off the painted eaves, and even if there were - there are no external vents!

 

phew ... that's a relief to know thank you, it feels so much more relieved now

He hasn't actually been to the place yet and have only seen some photos I sent him requesting to paint the eaves to encapsulate. He strongly reccomended removal of the eaves instead of painting due to aforementioned reason.

On a side note, the brick work in the building appears to be quite consistent & blemish free where external vents are expected. Wouldn't they appear slightly different with marks left behind if there has been modification work made to block off the original external vents ?

 

The only difference in mine is a slightly different colour mortar around the new bricks. I had a brickie do it.

Yours may have been done decades ago. Or maybe they forgot to add them.

 

yes and maybe just from photos i have it's not very obvious ...so i'll have to check closer in person.
Your brickie did a very tidy job

Did you do anything to the internal vents or just left them as is ? I'm thinking of blocking mine with clear adhesive tape\contacts in case dust from behind the walls gets in ... not sure what could possibly be hidden behind the plaster hence the paranoid side of mine just wanted to block them all

 

I was insulating the walls so replaced the plasterboard - and when I did that I didn’t replace the vents.

I did it because of sustainability i.e. keeping cold air out. If I hadn’t replaced the vents I would have filled them in with plaster or no more gaps.

If you use clear adhesive it might peel the paint off after a few years when you try to remove it - so perhaps warm it with a hair dryer when you remove it.