Cleaning the tiles on a roof

[cycleking]

An cold-caller type person knocked on my door this morning, asking me if I wanted to have the tiles on my roof cleaned.

He said that the algae that builds up will damage the roof, or words to that effect. Being polite, I responded that I did not think algae damaged tiles. He then asked me if I had seen the roof of the house three doors down.

Well yes, I have, surprisingly enough. They cleaned it. But now instead of being dark red tiles, they look a lot paler. This looks to me like they have been abraided/scratched/scuffed/damaged. I thought the algae was from bird droppings when they (the birds) perch on the tv aerial.
Is the cleaning process causing more harm than good?

I am concerned that elderly people living on their own would be bamboozled into having "work" done, that in addition to not being necessary, is possibly detrimental to the tiles.

Your technical advice on this would be appreciated.

yes, it is true that moss can damage a roof this is because over time it can hold alot of moisture which can leak into areas of the roof and cause decay and erosion, in colder months the water will expand and cause further damage. This is why its important to maintain the roof on your property! some insurance companies will even deny claims if you dont have receipt for maintenance of your home. you should scrape the moss off using a roof scraper https://roofscraper.co.uk/ which is a tool specifically made to remove moss from roofs I recently bought one to clean my bungalow roof. it is hard work though!

 

[midlife]

Is this thread over a decade old?

 

[MontyVeda]

Is this thread over a decade old?

yes, imagine how bad the algae is now!

edit... it's probably lichen anyhoo

 

[MontyVeda]

yes, it is true that moss can damage a roof this is because over time it can hold alot of moisture which can leak into areas of the roof and cause decay and erosion, in colder months the water will expand and cause further damage. This is why its important to maintain the roof on your property! some insurance companies will even deny claims if you dont have receipt for maintenance of your home

you do know the difference between moss and algae, don't you?

edit... it's probably lichen anyhoo

 

[twentysix by twentyfive]

Or liverwort

 

[Rusty Nails]

When I was a young teenager I used to work for my uncle on weekends and holidays as a jobbing builder. He wasn't that keen on heights and used to get me to do a lot of roofing works such as repointing chimneys, changing slates and renewing lead flashing.

He was a bit of a shark and used to get me to take off slates, turn them round and refit them so they looked like new from the ground. I also had to clean lead flashing with wire wool so that also looked like new. He knew that people would not climb up on to the roof to inspect it.

Looking back, I am ashamed of it but it has taught me never to accept a builder's work without checking it.

 

[biggs682]

It's just like washing your bike

 

[newts]

Your roof is much more likely to have leaking issues after the travellers (professional roofers) have been at it with a pressure washer removing surface algae together with cracking several tiles in the process of trampling all over. Last year our neighbour had the same professional treatment on her lovely printed/coloured concrete 10 year old driveway. Now it has lost all its colour, integrity & resembles the Sahara desert with the new powdery surface 😔🙄