From Newsgroup: uk.d-i-y

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?
--

Mike
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss
and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They
will set up scaffold towers and use long poles https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss
and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They
will set up scaffold towers and use long poles >https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.
--

Mike
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

Mike Halmarack <mikehalmarack@gmail.com> wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss
and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They
will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

I hope Mrs Halmarack doesnrCOt use a deodoriser/sanitiser in the washing machinerCathey can contain circa 2% BACrCa
--
Spike

--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29 Aug 2025 15:13:05 GMT, Spike <aero.spike@mail.com> wrote:

Mike Halmarack <mikehalmarack@gmail.com> wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss >>> and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They >>> will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

I hope Mrs Halmarack doesnAt use a deodoriser/sanitiser in the washing >machineathey can contain circa 2% BACa

That may eventually swing it.
--

Mike
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29/08/2025 15:56, Mike Halmarack wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss
and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They
will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

Unfortunately, since moss was reclassified as a plant it is illegal to
use BAC to kill it. However, as far as I'm aware there is nothing to
stop you using the detergent properties of BAC to clean the roof tiles
(other than The Management, of course...). <https://www.hse.gov.uk/biocides/copr/requirements.htm>
--
Jeff
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

Spike <aero.spike@mail.com> wrote:

I hope Mrs Halmarack doesnrCOt use a deodoriser/sanitiser in the washing machinerCathey can contain circa 2% BACrCa

Or indeed many kinds of domestic antibacterial cleaning sprays or wipes, eg: https://en.wikipedia.org/wiki/Dettol

Theo
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

Spike wrote:

Mike Halmarack wrote:

I liked the idea of the chemical solution, but my

wife has put me in the dog house for even considering it.

I hope Mrs Halmarack doesnrCOt use a deodoriser/sanitiser in the washing machinerCa

Or eye drops

they can contain circa 2% BACrCa

about 1/10th the level

--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On Fri, 29 Aug 2025 16:37:59 +0100, Jeff Layman wrote:

On 29/08/2025 15:56, Mike Halmarack wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the
moss and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc (BAC50 is a 50% solution of
Benzalkonium chloride which can be diluted x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them.
They will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267 https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

Unfortunately, since moss was reclassified as a plant it is illegal to
use BAC to kill it. However, as far as I'm aware there is nothing to
stop you using the detergent properties of BAC to clean the roof tiles
(other than The Management, of course...). <https://www.hse.gov.uk/biocides/copr/requirements.htm>

Isn't there a trick with a length of copper wire along the apex ?
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29/08/2025 17:38, Jethro_uk wrote:

On Fri, 29 Aug 2025 16:37:59 +0100, Jeff Layman wrote:

On 29/08/2025 15:56, Mike Halmarack wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats >>>>> here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the
moss and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc (BAC50 is a 50% solution of >>>> Benzalkonium chloride which can be diluted x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them.
They will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267 https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

Unfortunately, since moss was reclassified as a plant it is illegal to
use BAC to kill it. However, as far as I'm aware there is nothing to
stop you using the detergent properties of BAC to clean the roof tiles
(other than The Management, of course...).
<https://www.hse.gov.uk/biocides/copr/requirements.htm>

Isn't there a trick with a length of copper wire along the apex ?

Possibly, but if the intention is to use "leached" copper from the wire
to kill the moss, that would come under the COPR.
--
Jeff
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

Mike Halmarack <mikehalmarack@gmail.com> wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss >and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They >will set up scaffold towers and use long poles >https://www.youtube.com/shorts/a_n9LilAqr4 >https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

There's always that powerful chemical H20.
--
Chris Green
-+
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29/08/2025 16:13, Spike wrote:

Mike Halmarack <mikehalmarack@gmail.com> wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss
and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They
will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

I hope Mrs Halmarack doesnrCOt use a deodoriser/sanitiser in the washing machinerCathey can contain circa 2% BACrCa

I think dettol was full of it.
Or jeyes fluid.

I have found it the only thing that clears black patio pox
--
Future generations will wonder in bemused amazement that the early twenty-first centuryrCOs developed world went into hysterical panic over a globally average temperature increase of a few tenths of a degree, and,
on the basis of gross exaggerations of highly uncertain computer
projections combined into implausible chains of inference, proceeded to contemplate a rollback of the industrial age.

Richard Lindzen

--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29/08/2025 18:15, Jeff Layman wrote:

On 29/08/2025 17:38, Jethro_uk wrote:

On Fri, 29 Aug 2025 16:37:59 +0100, Jeff Layman wrote:

On 29/08/2025 15:56, Mike Halmarack wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats >>>>>> here. The roof has a big moss problem which is forever blocking the >>>>>> downpipes. Evident at critical moments.
I don't-a think the management are keen on having workers walking on >>>>>> the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the
moss and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over >>>>> three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc (BAC50 is a 50% solution of >>>>> Benzalkonium chloride which can be diluted x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them.
They will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267 https://youtu.be/EHnpDNVXtO4?t=540 >>>>

Thanks for the info. I liked the idea of the chemical solution, but my >>>> wife has put me in the dog house for even considering it.

Unfortunately, since moss was reclassified as a plant it is illegal to
use BAC to kill it. However, as far as I'm aware there is nothing to
stop you using the detergent properties of BAC to clean the roof tiles
(other than The Management, of course...).
<https://www.hse.gov.uk/biocides/copr/requirements.htm>

Isn't there a trick with a length of copper wire along the apex ?

Possibly, but if the intention is to use "leached" copper from the wire
to kill the moss, that would come under the COPR.

Put it up there for its decorative effect?
--
Sam Plusnet
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On Fri, 29 Aug 2025 16:38:29 -0000 (UTC), Jethro_uk <jethro_uk@hotmailbin.com> wrote:

On Fri, 29 Aug 2025 16:37:59 +0100, Jeff Layman wrote:

On 29/08/2025 15:56, Mike Halmarack wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats >>>>> here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the
moss and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc (BAC50 is a 50% solution of >>>> Benzalkonium chloride which can be diluted x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them.
They will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267 https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

Unfortunately, since moss was reclassified as a plant it is illegal to
use BAC to kill it. However, as far as I'm aware there is nothing to
stop you using the detergent properties of BAC to clean the roof tiles
(other than The Management, of course...).
<https://www.hse.gov.uk/biocides/copr/requirements.htm>

Isn't there a trick with a length of copper wire along the apex ?

Which will work. Do this only if the gutters etc. are copper (or plastic, I guess) as well: otherwise the copper runoff "eats" the zinc, steel, or galvanized steel guttering...


Thomas Prufer
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29/08/2025 13:55, alan_m wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't-a think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss
and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They
will set up scaffold towers and use long poles https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

I've always resisted this idea because all our down pipes have diverters
to water butts attached. Excess rainwater then goes to soakaways so it probably won't do them any good either & I don't really want to
experiment to find out.
--
Regards
wasbit
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29/08/2025 16:37, Jeff Layman wrote:

On 29/08/2025 15:56, Mike Halmarack wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of flats
here. The roof has a big moss problem which is forever blocking the
downpipes. Evident at critical moments.
I don't-a think the management are keen on having workers walking on
the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the moss
and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust over
three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be diluted
x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them. They
will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but my
wife has put me in the dog house for even considering it.

Unfortunately, since moss was reclassified as a plant it is illegal to
use BAC to kill it. However, as far as I'm aware there is nothing to
stop you using the detergent properties of BAC to clean the roof tiles (other than The Management, of course...). <https://www.hse.gov.uk/biocides/copr/requirements.htm>

Doesn't seem to mention lichen which often lives along side moss.
--
Regards
wasbit
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 29/08/2025 16:51, Andy Burns wrote:

Spike wrote:

Mike Halmarack wrote:

I liked the idea of the chemical solution, but my

wife has put me in the dog house for even considering it.

I hope Mrs Halmarack doesnrCOt use a deodoriser/sanitiser in the washing
machinerCa

Or eye drops

Until you become sensitised to the awful stuff and wake
up in the night looking like one of those chinese dogs
with lots of flappy skin in their face.

Then you need the NHS to provide the preservative-free
versions, but the label on Cosopt or its generic versions
says 'Do not refridgerate or freeze, or store above 25C'.

Tricky this summer.

Spraying BAC onto the roof of a 3 story building from
the ground sounds like a really daft idea, unless you
are wearing a full Nuke/Biological protection suit.

--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 30/08/2025 17:12, Andrew wrote:

On 29/08/2025 16:51, Andy Burns wrote:

Spike wrote:

Mike Halmarack wrote:

I liked the idea of the chemical solution, but my

wife has put me in the dog house for even considering it.

I hope Mrs Halmarack doesnrCOt use a deodoriser/sanitiser in the washing >>> machinerCa

Or eye drops

Until you become sensitised to the awful stuff and wake
up in the night looking like one of those chinese dogs
with lots of flappy skin in their face.

Then you need the NHS to provide the preservative-free
versions, but the label on Cosopt or its generic versions
says 'Do not refridgerate or freeze, or store above 25C'.

Tricky this summer.

Spraying BAC onto the roof of a 3 story building from
the ground sounds like a really daft idea, unless you
are wearing a full Nuke/Biological protection suit.

The professionals use long hollow poles to deliver the diluted chemical
to the roof and a brush type head to spread it on the tiles. It's a
similar method that window cleaners use these days use to deliver
de-ionised water to the brush to clean to upper storey windows.
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: uk.d-i-y

On 16:26 29 Aug 2025, Mike Halmarack said:

On 29 Aug 2025 15:13:05 GMT, Spike <aero.spike@mail.com> wrote:

Mike Halmarack <mikehalmarack@gmail.com> wrote:

On Fri, 29 Aug 2025 13:55:02 +0100, alan_m <junk@admac.myzen.co.uk>
wrote:

On 29/08/2025 09:58, Mike Halmarack wrote:

There is a concrete tile pitched roof on the 3 storey block of
flats here. The roof has a big moss problem which is forever
blocking the downpipes. Evident at critical moments.
I don't think the management are keen on having workers walking
on the roof with pressure hoses.
So is there a known better solution?

Benzalkonium chloride sprayed on from the ground. It will kill the
moss and keep it clear for a few years, so spray every 2/3 years.

The moss will be killed almost immediately and turned to a dust
over three months or so - the rain will wash it off.
You may/will need clear gutters before treating.

https://www.youtube.com/shorts/Ohwd7MrW2Nc
(BAC50 is a 50% solution of Benzalkonium chloride which can be
diluted x10 for roof cleaning).

Reputable companies don't pressure was roofs by walking over them.
They will set up scaffold towers and use long poles
https://www.youtube.com/shorts/a_n9LilAqr4
https://youtu.be/EHnpDNVXtO4?t=267
https://youtu.be/EHnpDNVXtO4?t=540

Thanks for the info. I liked the idea of the chemical solution, but
my wife has put me in the dog house for even considering it.

I hope Mrs Halmarack doesnAt use a deodoriser/sanitiser in the
washing machineathey can contain circa 2% BACa

That may eventually swing it.

BAC is even found in many mouthwashes. Fairly safe stuff.

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