'Lead alternative' flashing

[JohnW2]

I realise that I'm not the first person to have asked this, but I wonder if you can help me understand? ....

What is the difference, other than price, between the various (usually self-adhesive) 'repair' products (which seem to be generally frowned upon around here) and 'proper' lead alternatives (for flashing) such as Flashband etc. and the 'proper' lead alternatives, such as Ubiflex and Leadax? Is it perhaps a matter of thickness, is there a fundamental difference about the material/construction, or what?

Putting the question in a more practical way, if I used a product like FB 'properly' (chasing it in, etc.) in what way(s) would the result be inferior to using one of the more expensive products (or even lead itself)? Is it just a question of longevity (In my situation, I would not be wanting 'decades'), or what?

Kind Regards, John

 

[catlad]

Hi John
Flash band is definitely a diy product and should last 10 yrs
ubiflex is a more professional alternative to lead that I've used many times and should last 20+ yrs. Lead will last a lifetime if used correctly.

 

[JohnW2]

Hi John, Flash band is definitely a diy product and should last 10 yrs
ubiflex is a more professional alternative to lead that I've used many times and should last 20+ yrs. Lead will last a lifetime if used correctly.

Hi catlad,

Thanks. As I implied, I suspected that it was probably primarily a matter of 'longevity'. As I said, I'm not looking for 'decades', since I suspect that the entire flat roof in question will probably benefit from (maybe 'need'!) to be completely re-done within 10 years or so.

So, to be clear, are you saying that, if installed reasonably well, Flashband ought to 'do the job' for at least 'a few years'? ...and, as a matter of interest, to repeat my initial question, how does it differ from the likes of Ubiflex - thickness, material, construction or what?

Kind Regards, John

 

[catlad]

Well ideally all flashing should be chased into the wall and then sealed, which is where ubiflex is ideal as it also has its own mastic sealer. Flashband is much thiner and can be applied directly to the wall as it has a sticky side, it won't stick at this time of year without a blow lamp and a primer.

 

[JohnW2]

Well ideally all flashing should be chased into the wall and then sealed, which is where ubiflex is ideal as it also has its own mastic sealer. Flashband is much thiner and can be applied directly to the wall as it has a sticky side, it won't stick at this time of year without a blow lamp and a primer.

Thanks again. I would certainly be chasing it into the wall (not just relying on it sticking to the wall), but what do you mean by 'then sealed' - do you mean 'sealed into the chase' (which I would do, with mortar or some sealant) or something else?

Sorry about all the questions!!

Kind Regards, John

 

[catlad]

Hi John
if you look at roofing superstore and type in ubiflex the sealant should come up as people also bought this product. If you do a decent job now there is no reason it can't be kept as you renew the roof in a few years

 

[catlad]

It's called a gap sealant.

 

[JohnW2]

Hi John .... if you look at roofing superstore and type in ubiflex the sealant should come up as people also bought this product. If you do a decent job now there is no reason it can't be kept as you renew the roof in a few years

It's called a gap sealant.

Yes, I'm familiar with the sealant, but I was asking what 'gap' you were talking about sealing - that where the flashing was chased into the wall, or somewhere else?

I doubt that I would use the likes of Ubiflex/Leadex etc., since they do not appear to be markedly (if at all) cheaper than lead, which is why I was talking about the ("DIY") 'flashing tape' products like Flashband.

I'm personally only familiar with using Bostik/Evo-Stick "Flashband", but there seem to be a lot of other brands around (Bond It, Denso, Soudal etc.) - do you know if there is anything to choose between them?

Kind Regards, John

 

[RandomGrinch]

Yes, I'm familiar with the sealant, but I was asking what 'gap' you were talking about sealing - that where the flashing was chased into the wall, or somewhere else?

Yes, the gap sealant is for filling the chase, or the mortar course - a simpler solution for a contractor, applied quickly with a gun rather than mixing up mortar and dealing with the cleanup.
It's also flexible.

Ubiflex is an impregnated aluminium mesh, so it materially behaves in a similar way to lead - but benefits from being lighter, available in longer lengths and (a huge benefit for some!) has no resale value if stolen.

I'm personally only familiar with using Bostik/Evo-Stick "Flashband", but there seem to be a lot of other brands around (Bond It, Denso, Soudal etc.) - do you know if there is anything to choose between them?

Sorry, I don't know about the alternatives, but as a DIY'er, I've been happy with Flashband, my efforts have remained water tight for a couple of years now.
It's also available to me locally through Screwfix/Toolstation.
...and as Catlad says, primer and a heatgun in this weather!

 

[JohnW2]

Yes, the gap sealant is for filling the chase, or the mortar course - a simpler solution for a contractor, applied quickly with a gun rather than mixing up mortar and dealing with the cleanup. It's also flexible.

Thanks for your interest, and thanks for clarifying/confirming.

Ubiflex is an impregnated aluminium mesh, so it materially behaves in a similar way to lead - but benefits from being lighter, available in longer lengths and (a huge benefit for some!) has no resale value if stolen.

Yes, that's what I thought, but that's one of the more expensive 'proper' alternatives to lead. Do you know if the (cheaper) 'flashing tapes'(like Flashband) have a similar construction, and maybe are just a bit thinner - or is there some other fundamental difference?

Sorry, I don't know about the alternatives, but as a DIY'er, I've been happy with Flashband, my efforts have remained water tight for a couple of years now.
It's also available to me locally through Screwfix/Toolstation.

As I said, allof my past experience has been with Flashband, so that's what I would plan to use. I just wanted to be sure that there was nothing similar which was regarded as 'better'.

...and as Catlad says, primer and a heatgun in this weather!

Fair enough, but I don't think I would be relying upon the Flasband's adhesive, anyway.

Kind Regards, John

 

[RandomGrinch]

'flashing tapes'(like Flashband) have a similar construction, and maybe are just a bit thinner - or is there some other fundamental difference?

According to Bostik:

And a thickness of 1.3mm.

Ubiflex has a thickness of between 2.3 and 3.5mm

The fundamental difference to me - floppy and sticky Vs stiff, (relatively) self supporting and unsticky!

 

[JohnW2]

According to Bostik: .... And a thickness of 1.3mm. .... Ubiflex has a thickness of between 2.3 and 3.5mm

Thanks. I guess that's consistent with a roughly 2:1 price difference.

The fundamental difference to me - floppy and sticky Vs stiff, (relatively) self supporting and unsticky!

Yes, it sounds as if that is a pretty good summary, but I'm not sure that it will persuade me tto go for the latter!

Kind Regards, John

 

[robinbanks]

Not sure that the aluminium layer in flashband would take kindly to being mortared over, and that's the layer that would give the UV resistance to stop the sun destroying the rest of it

Leadax is an expanded Alu mesh coated in a lead coloured squishy plastic and for the most part behaves a lot like lead, though it does spring back a little when being shaped whereas lead doesn't. Agree with carload's notion that you could chase a lead alternative flashing in now, clip and seal it and in 10 years it'll just bend up out the way, fit a new roof and then bend down again. Flashband I'm less confident would do the same

 

[blup]

There are currently five "similar threads" showing at the end of this thread, they all look helpful

Blup

 

[JohnW2]

Not sure that the aluminium layer in flashband would take kindly to being mortared over, and that's the layer that would give the UV resistance to stop the sun destroying the rest of it

It's a while since I last handled, or had to hand, any Flashband, but isn't the aluminium layer below the 'rest of it' which may need to be protected from UV? I'm not sure what sort of 'not taking kindly' you are thinking of. However, even if the aluminium were exposed, and there were some chemical problem with mortar, one could presumably use some sort of sealant/mastic instead?

Leadax is an expanded Alu mesh coated in a lead coloured squishy plastic and for the most part behaves a lot like lead, though it does spring back a little when being shaped whereas lead doesn't.

Fair enough.

Agree with carload's notion that you could chase a lead alternative flashing in now, clip and seal it and in 10 years it'll just bend up out the way, fit a new roof and then bend down again. Flashband I'm less confident would do the same

Yes, I understand and agree with that -and the same would obviously be at least as equally true with lead. However, as I've said, I'm not sure that, in my situation, I would go for something like Leadax/Ubiflex, since the price differential from lead is then not very great, soI then might as well use lead. Theft/re-sale value is not really an issue, given the location and the (difficult!) access to the roof - other than that, are would there be any appreciable advantage in using an alternative' rather than lead itself (if I wanted to spend that much)?

It really is essentially a 'temporary' (maybe 'a few years'), and ideally inexpensive, approach I'm looking for. Although still largely watertight (except at one edge, hence this thread!), the (pretty large) flat roof is well past its sell-by date, and will very probably need re-doing within a decade or so - but that will very probably be "someone else's problem"

Thanks for your interest and assistance.

Kind Regards, John