Moss on Roof

[corrie]

Good tech that mate. I give an honest opinion based on 35 yrs as a Slater who has proven on many an occasion that moss can and does cause ingress on a roof. As far as making money on it is concerned?....It`s not something I go out of my way to advertise or do . It could be that your opinion is based on unskilled ****** with power washers damaging peoples property rather than enhancing it .

Customer........"I have water ingress in this location" Me " Detail checks out ok except for moss which I have cleaned thoroughly" Put buckets back where they were collecting water..........RESULT. Same scenario on many occasions with Slates ..Rosemary and interlocking Concrete.

Of course there will be roofs with moss that have no ingress to roofspace.....just as there are people who smoke and do not have cancer.
The chances are still that if you remove a tile there will be some ingress on battens and felt though. I have posted this for the forum members and they can make their own mind up. Obviously you have already made up yours..........and you are wrong.

Corrie

 

[noseall]

capillary action can only work against gravity when two surfaces are close together.

this problem was alleviated by cambering plain tiles.

in other words PREVENTING tiles from fitting so snugly together.

how can moss 'cause' capillary action?

 

[corrie]

Yes and the camber also eases fitment in riding over nails and makes the final result more pleasing.
Your example of the camber is before the moss has come into the equation. Once moss interferes with run off dirt builds up behind it.

The meniscus or dam effect can now take place. It spills over the water channels of interlocking tiles and has the habit of finding nailholes in slates or Rosemary where it is driven by the wind. When it is driven up it fans out before coming back down. Most capillary type action on roofs is helped by updraught. The camber on Rosemary type doesn`t actually help now because it has stolen some of our pitch. Where slates are nailed through sarking this can cause instant ingress. Even if nailed on battens it is now onto the felt.

It can also have an Osmosis type effect on tiles themselves as it interferes with the Wet /Dry process. That in itself is another hazard where frost is concerned. Hope this helps.

Corrie

 

[noseall]

no it does not help.

i have seen a roof practically covered in moss, so much so that it actually needed mowing.

bone dry beneath.

i personally have never seen or dealt with a roof water ingress problem that was attributed to moss on the roof.

nor have i heard of any roofers talking about it.

it is strange that moss has suddenly become a problem since the advent of 'roof coating' companies.

 

[noseall]

Yes and the camber also eases fitment in riding over nails and makes the final result more pleasing.
Your example of the camber is before the moss has come into the equation. Once moss interferes with run off dirt builds up behind it.

The meniscus or dam effect can now take place. It spills over the water channels of interlocking tiles and has the habit of finding nailholes in slates or Rosemary where it is driven by the wind. When it is driven up it fans out before coming back down. Most capillary type action on roofs is helped by updraught. The camber on Rosemary type doesn`t actually help now because it has stolen some of our pitch. Where slates are nailed through sarking this can cause instant ingress. Even if nailed on battens it is now onto the felt.

It can also have an Osmosis type effect on tiles themselves as it interferes with the Wet /Dry process. That in itself is another hazard where frost is concerned. Hope this helps.

Corrie

utter and total hogwash.

the only problem with moss is that:

a. it holds water and can be a problem to delaminated tiles in extremes of cold weather.

..........a delaminated roof would require re-tiling in any case.

b. it can clog up gutters and water run offs.

..........so can leaves, at least moss tends to stay put.

osmosis! that is hysterical f.f.s.

 

[corrie]

Ok . The mention of Roof painting seems to be where you are coming from. Roofs were never meant to be painted and never should be. You choose to ignore the situation and facts that I have stated.......fine.

You cannot be expected to believe things which

A You have no experience of........as you stated

B No one has told you about.........as above

Moss can and has caused ingress since my old Dad served his time as a Steeplejack and he is 80 now. I will tell him what you said..........it should give him a laugh. I learned this when I served my time with him as a Slater. It has proven invaluable since. Maybe people aint giving you their secrets because you know it all anyway .

If water can and does seep into a fibregalss boat hull. what makes you think it doesn`t creep through cheap concrete roof tiles. You sound like one of those guys who told us Asbestos would do no harm in the 60s

Finally I take it you have come across Cast Iron Skylights? 9 times out of 10 when one has Ingress at that area look at it closely.....what do you see? I`m assumming you go up and look at these things.

Each side of the skylight is a facsimile of the left hand side of a concrete tile. When that blocks up with WHATEVER the water still comes into frame at head of window .Where does it go?. That is what happens with concrete tiles. It is quite a good earner for Slaters that one

Anyway people can look at the facts, they are in the posts. I merely offer my experience.......I care not whether it is ignorance. nor if it is your post count or your ego........but once again you are wrong.

Corrie

[/u]

 

[noseall]

at no time have i stated that water does not find its way into a roof space.

i don't deny it, far from it, i concur with the fact that clogged water channels can cause water to back up into a roof via a roof light, a lead or grp valley, blocked gutter, etc....

at no time however do i subscribe to the fact that moss can cause water to enter a roof by means of "OSMOSIS" (ha, ha, ha,) "CAPILLARY ACTION" (ha, ha, ha, ha,) "MENISCUS OR DAM EFFECT" ( ho, ho, ho, ha, ha, ha,).

water can not arbitrarily penetrate a g.r.p, lead, concrete or clay product unless that product is faulty, full stop.

moss will not change this.

and neither can you prove, that the very presence of moss, on a regular pitch roof, i.e. without valleys or interruption to the 'run off zone' can cause water to enter the roof.

 

[Mw Roofline]

 

[corrie]

The meniscus or dam effect is the one which you concur too. You just don`t admit that moss can cause the "Clogging" effect anywhere on the roof Better get some oil on that bicycle chain as the noise of you back pedalling there was as loud as the grotesque ho ho ha ha

All tiles on roofs will eventually be "faulty". Moss will speed this up. I used Grp as an illustration of Osmosis as some think it totally waterproof. I did not say that Osmosis effects causes water to come in a roof I made the point that it could creep through old roof tiles and although not causing a rain drop is undesirable in itself.
My purpose was to show that old tiles on old roofs can be permeable . This causes water to be right through the tile and then with frost can lead to Spalting or cracking. I only use lead flashings on roofs.

As for the Laughing Gnome comments. Your post will only be remembered for saying that Moss in any shape or form cannot cause water ingress. In fact you probably think it looks quite nice. You may have Ivy growing up your Roughcast as well .

As for proof. The proof is that I believe it. Because I have seen it and remedied it so many times. Cause and Effect. Do you get up on roofs much? I hope to get some better advice on building etc than you have given me on roofing



Corrie

 

[noseall]

As for proof. The proof is that I believe it.

Corrie

....mmmmm, i beleive in Father Christmas, so i guess we are both right eh?

 

[corrie]

You know that is so true. If you believe in God . Your belief is a fact. It does not prove a God.....or disprove one........but the fact of belief remains. It may be stretching it to Sanity Clause right enough

Corrie