[JSMC]

got myself a job cleaning up a metal roof on an ind est. It is marked with dirt and these black mark which look like mossy / fungus or something. i sprayed TFR on it but feckin murder to ge toff still. Any ideas on wha will shift it?

Should i increase TFR strength?

roof has a paint coating on it also.

[Nathanael Jones]

Try Sodium Hypochlorite (double strength un-thickened bleach) if its just green/black algae on the roof,.. just spray it on and it should disappear. be careful though if you're walking up there, chems and water will make it real slippery, make sure you're ropes are on and secure at all times!

[Dean Taberner]

Internal or external of the roof,

The reason I ask is we helped Jv Price to do an internal roof clean on an ex bakery 2 weeks ago and TFR got all the crap off it with abit of elbow grease.

Dean

[JSMC]

external cleaning. Also working off ladder with pole. Cannot walk on roof. only corrugated metal which is on mos tindustrial units. ye know the type ? raised section every few inches. These are not to be wlaked on. You would need to walk where the studs are on the roof i reckon. Not a high roof pretty low. Dont even have to open my ladder to ge tup to it.

[Nathanael Jones]

external cleaning. Also working off ladder with pole. Cannot walk on roof. only corrugated metal which is on mos tindustrial units. ye know the type ? raised section every few inches. These are not to be wlaked on. You would need to walk where the studs are on the roof i reckon. Not a high roof pretty low. Dont even have to open my ladder to ge tup to it.

Try the bleach,.. if it works you can use a pressure washer and X-jet to spray huge area's really quick.

[JSMC]

have a pressure washer but waiting some bits n bobs being delivered. problem isw at ind est i have no access to water supply as working over weekend and all units closed up.

[Gleaming windows]

Sounds like lichen to me.





Is this it?

[Andy Foster]

Why not use a cherry picker and get above it to either pressure clean or steam it?
Seems the easiest, safest and would give you the best results.

[JSMC]

problem would be back of units where it's like a ploughed field LOL.

[JSMC]

Sounds like lichen to me.





Is this it?

that looks like it. seems embedded onto metal

[Gleaming windows]

If it is lichen then chemicals wont clear it (TFR). You'll have to do it by mechanical means, pressure washer etc.

Lichen is a nightmare even after youve got the main body of it off theres still a 'footprint' of it left, You get it on conservatory roofs quite often, a good scraper helps in those situations but not on something that is the size of an industrial unit.

[JSMC]

been reading that copper sulphate kills it off

[Nathanael Jones]

been reading that copper sulphate kills it off

True,.. as does MossGo Pro,... but it takes MONTHS to clear completely.

I'm testing a couple of roof cleaning chems at the moment & I'm disgusted at hos slow they are to work!

[Moderator David@stives]

Lichen only grows where the air is clean.

Be careful with the bleach, i know local authorities dont like you using it, it is also banned from being used at the schools I clean

[JSMC]

gonna be a nightmare to clean this off i reckon. Reckon i will eithe rspray osme bleach mixture or copper sulphate and leave ofr a week or so then go back and wfp if all off

[Craig Trevain]

Better to use Acid than alkoli (Hydrachloric acid best) this kills it quickly, and a polarspray (ebay) would be good to apply it with.

[Nathanael Jones]

Lichen only grows where the air is clean.

Be careful with the bleach, i know local authorities dont like you using it, it is also banned from being used at the schools I clean

This is what I use in places bleach use is restricted:
http://www.mistral.ie/details.php?code=R6120

It dissolves in water to produce a hydrogen peroxide based bleach. It's great for washing decking & timber fences as it doesn't bleach the colour from the wood. It breaks down into water in only a few hours though, which makes it very eco friendly, but you have to remember only to mix what you're going to use straight away.

I find Sodium Hypochlorite works better & quicker though

[JSMC]

you reckon that will kill the lichen? spray it on leave for a week then return?

[Nathanael Jones]

It'll kill algae no problem,... lichen i've not tried it on.

I tested it on my shed roof which is covered in moss,.. it killed the moss almost straight away, but the dead moss is still there 3 weeks later, hardly any of it has dropped off naturally & I'd assume Lichen would be the same. It might make removal easier, but you'll prob still have to scrub it.