Roof Cleaning - Scrape or Pressure Wash

[Pjj]

I was talking about render and concrete precast tiles not slate tiles

so was I ??? hypo will kill everything that’s on the tile and it does soak in as well I have done extensive testing with both hypo and bio and have found the clean lasts longer with hypo than bio , it also gives much quicker results.The tiles in the picture are concrete .

 

[Part Timer]

so was I ??? hypo will kill everything that’s on the tile and it does soak in as well I have done extensive testing with both hypo and bio and have found the clean lasts longer with hypo than bio , it also gives much quicker results.The tiles in the picture are concrete .

You can obviously see where you have bleached the tiles but the algi on the ridge tiles seems the same as next doors

 

[Pjj]

You can obviously see where you have bleached the tiles but the algi on the ridge tiles seems the same as next doors

The pictures were taken after 5 muinits of applying the first coat, orange/ yellow liken is the hardest to kill ,and takes a couple of hours to change colour after a second coat and a few hours it has turned a dark red and is dying , bio would take 6 months at least to kill it off , it was a very heavy infestation with loads of moss as well . It could really have done with scraping first , but the customer opted for just having it sprayed .

 

[Pjj]

If you zoom in on the pictures you can see a difference on the ridge tiles and that’s only one coat and and the mix has only been on there 5 muinits already it’s starting to break up .

 

[K in Kent]

It doesn't damage the tiles IMO, we 'steam clean' 90% of roofs and have no issues.

We don't steam clean if the roof looks knackered (potential leaks) or if they've got newish concrete tiles (adding years of weathering to the coating)

Clay and slate are the same colour all the way through so they get steamed.

Tile manufactures are always going to advise against getting your roof cleaned as the more roofs cleaned the less tiles they'll sell

No they're in favour of proper maintenance and moss removal and are not against cleaning, just jet washing because it can strip the outer coating.

 

[THL4KEL]

Just get a decent set of scrapers if youre worried about pressure washing - Marshall Pro is the best to buy.

 

[tench0771]

 

[tench0771]

That’s my roof almost 3 years since it was sprayed with Benz biocide I’ve always found biocide very good just takes a while to do the biz ?

 

[Arnoldtailor]

Scrape or Pressure Wash?

What's your method of choice?

I personally have been a scrape it person, but im seeing more and more people just going straight in with the pressure washer. I was always lead to believe that pressure washing damages the roof tiles, but have i been miss informed?

I've always been a bit cautious about pressure washing roof tiles. Scraping has been my go-to because I worry about potential damage with too much pressure. However, I've seen folks successfully use pressure washers without causing harm. It really comes down to the technique and the setting on the washer. If you're considering switching, maybe start on a small area to test it out. But always trust your gut, and when in doubt, consult with a roofing expert. Better safe than sorry!

 

[scottish cleaning service]

I just spray them now with hypo and if they want me to come back and brush off the moss then
I charge for that service now.

 

[Truckcab79]

I've always been a bit cautious about pressure washing roof tiles. Scraping has been my go-to because I worry about potential damage with too much pressure. However, I've seen folks successfully use pressure washers without causing harm. It really comes down to the technique and the setting on the washer. If you're considering switching, maybe start on a small area to test it out. But always trust your gut, and when in doubt, consult with a roofing expert. Better safe than sorry!

Don’t consult one of these ‘roofing experts’. Photographed these chaps last week. ‘Proper’ roofing company at least according to their van. 3 of them spent all day up there with hand scrapers. Not so much as a ridge hook ladder to support them. Must be insane.

To be fair they did a nice job. ?.

 

[scottish cleaning service]

I just spray roofs with hypo now if they want it done another way then I tell them its not for me.

 

[Deleted member 5762]

I don't do any roof cleaning myself. I know a roofer who advised only to scrape and then use a biocide after. He said he'd never recommend pressure washing and/or using hypo. Then again on YouTube nearly all the videos you see now are pressure washing of roofs ??

 

[K in Kent]

Tile manufacturers Marley state :

The use of high powered jet washes is not recommended as it can damage the surface of the slate or tile, thus reducing its expected life considerably.

Roof Tile Association state :

On no account should a high pressure water jet be used to clean off moss and lichen growths from concrete
tiles. This will result in erosion of the surface thereby reducing the potential lifespan of the roof tile.

I understand the temptation to pressure wash and if you're choosing that option the best bet has got to be with a FSC. It's an effective, safer and tidier way of doing it that avoids the potential mess and risks of lifting tiles etc. But you need to be aware of what the manudactirers and experts say on the subject.
Forticrete are another major UK tile manufacturer and I know they also warn against p/w.
Personally I prefer a scrape and soft wash and don't think you can beat a hypo mix when it comes to cleaning and removing algae, lichen etc.
They are usually a fairly straightforward type of job that can have dramatic results and pay very well.

 

[Pjj]

View attachment 29360

Don’t consult one of these ‘roofing experts’. Photographed these chaps last week. ‘Proper’ roofing company at least according to their van. 3 of them spent all day up there with hand scrapers. Not so much as a ridge hook ladder to support them. Must be insane.

To be fair they did a nice job. ?.

Lol Health and safety is non existent there are some right cowboys out there

 

[Herm]

having pressure washed one roof, I shall never ever be doing it again! unless you've done it you can't even comprehend the amount of mess it makes and you spend hours if not a day cleaning up afterwards. We only now scrape and spray, it's far easier and quicker.

 

[K in Kent]

having pressure washed one roof, I shall never ever be doing it again! unless you've done it you can't even comprehend the amount of mess it makes and you spend hours if not a day cleaning up afterwards. We only now scrape and spray, it's far easier and quicker.

The way I've always looked at iz is : just look at the mess it makes on the ground, never mind up in the air, thick with moss and a bit of wind! It's likely to be not only the customers property but the neighbours as well that you've got to clean up

 

[scottish cleaning service]

The way I've always looked at iz is : just look at the mess it makes on the ground, never mind up in the air, thick with moss and a bit of wind! It's likely to be not only the customers property but the neighbours as well that you've got to clean up

The last and final one I did, I laid salvage sheets all over the place. Never again took me the same time to PW roof and to clean up each side. I just offer to spray and now I don't go back and brush the moss off.

 

[K in Kent]

That's absoliutely fine, and of course it's down to the individual to decide what service you want to offer and what it is customers want.
In my personal experience they want the full works, i.e. moss removal, moss inhibiting treatment and tiles left looking like new.
I view it as a luxury service but quite alot of people are willing to pay for it. As with all things, the more you do it the easier it gets and your confidence grows. The job may take a few days and it can be hard work at times, but if it's been well priced there is decent money to be made. You just need to know the value of the service you;re offering and how it compares to the local competition. When customers aren't willing to pay it, don't take it on. But there is definitely a market out there for professional roof cleaning services.

 

[THL4KEL]

If the roof has heavy moss better off scraping it before you pressure wash it. Always good to disconnect the Downpipe and fit one of these -

https://www.ebay.co.uk/itm/254954326036?hash=item3b5c764814:g:8PwAAOSwol5gg~qg&amdata=enc%3AAQAIAAABIH03xlF7vkiA0mkTYEN93ICQVJ1MgWYCssXsNrwUIsuhTsQBwc78JX%2FAra0O8SS1dEnB6SsocZnZD43mGRkiJU4gOhI0UC%2BoJR9xIq8%2FEajGGkmk4HRUmMaIV3J0KGX0BJCVpGI4Sc6tCSRJG6NSj0onXkL3w8BOGhRSlXMGuWAvDa36Ek7TPZ6W%2BW%2FdhH6De%2BFr%2F4GpUxhaqCEQneZqP7Hn7vvmt2A8xs3xDhgNYyq2NiROtaif19Y%2F8FKQP7VL%2F8%2FJ9afDmA80Vv2apAzrAXP3iCk%2Bd2sGpxItMD5XQJ2GAUkgvrw4n1NoAynGWgn0XcF1qi3h6%2FiqUcTE%2FDpNEuSYtUAkg9IDp0Bh1b42Q99v8bfS%2Fiihe3Th1LECj63d7w%3D%3D%7Ctkp%3ABFBMoqLmvfZi

Then you can send the water to a suitable place...

Buy a massive piece of tarp as well. Think I have a 8mx5m. Always handy to have the gutter vax available as well.

 

[Part Timer]

If the roof has heavy moss better off scraping it before you pressure wash it. Always good to disconnect the Downpipe and fit one of these -

https://www.ebay.co.uk/itm/254954326036?hash=item3b5c764814:g:8PwAAOSwol5gg~qg&amdata=enc%3AAQAIAAABIH03xlF7vkiA0mkTYEN93ICQVJ1MgWYCssXsNrwUIsuhTsQBwc78JX%2FAra0O8SS1dEnB6SsocZnZD43mGRkiJU4gOhI0UC%2BoJR9xIq8%2FEajGGkmk4HRUmMaIV3J0KGX0BJCVpGI4Sc6tCSRJG6NSj0onXkL3w8BOGhRSlXMGuWAvDa36Ek7TPZ6W%2BW%2FdhH6De%2BFr%2F4GpUxhaqCEQneZqP7Hn7vvmt2A8xs3xDhgNYyq2NiROtaif19Y%2F8FKQP7VL%2F8%2FJ9afDmA80Vv2apAzrAXP3iCk%2Bd2sGpxItMD5XQJ2GAUkgvrw4n1NoAynGWgn0XcF1qi3h6%2FiqUcTE%2FDpNEuSYtUAkg9IDp0Bh1b42Q99v8bfS%2Fiihe3Th1LECj63d7w%3D%3D%7Ctkp%3ABFBMoqLmvfZi

Then you can send the water to a suitable place...

Buy a massive piece of tarp as well. Think I have a 8mx5m. Always handy to have the gutter vax available as well.

I was told you should actually put one of those on if you biocide the roof to prevent the chemicals getting into the water system