Roof Maintenance?

[Doug99]

Hi All,

I live in a 25yr old Permmison built 4 bedroom detached house whose roof is now looking sorry for itself.

The roof doesn't leak and from ground level there does not appear to be any broken tiles (Marley Double Roman - identified via previous threads, thanks). The north facing side of the roof is however covered in a lot of 'moss' type of growth and in some areas this growth is to the size of golf balls, for which local birds find useful for their nesting materials. Some of the plastic mesh which prevents birds accessing the roof space appears to be damaged/missing. All the brown PVC guttering and downpipes have faded and need replacing. All weatherboards look sound and only need painting.

My query is what should I ask of my local roofers when I ask for quotes? The guttering and weatherboards are straight forward, however I do not wish to give the roofer free reign to check and offer to do work that may not be necessary.

I don't want to revisit the roof for another 25yrs so will a simple request to clean, check and repair any loose tiles be sufficient?

Cheers,

Doug

 

[Birminghamroofer]

This maybe the case although a closer inspection may find defects if the roof is covered in moss then really this needs to be removed and treated with an anti-fungacidal solution which will help prevent future growth.
If left unattended the moss will act as a sponge absorbing water and the tiles wont be able to allow the rainwater to disperse in the correct manor the growth is also a food substance for birds and in time the tiles may be affected by pecking order.
I strongly recommend removing all growth as it is only detrimental to the roof covering.
I hope i have been of some help and assistance in relation to your initial post.

 

[Alastairreid]

Moss and lichen growth
There is no evidence that mosses and lichens cause damage to or affect the strength of roof tiles. Mosses and lichens tend to grow on the surface of roof tiles because their rough surface filters dirt out of rainwater. Spores and seeds can be blown onto the roof or are carried there on the feet of birds and then take root in the dirt on the tiles. Sanded or granulated tiles tend to promote growth the soonest. Growth is also most likely to happen where there are trees nearby and in shady, damp conditions, particularly on North-facing roof slopes.

The principal effect of moss and lichen growth is that it can hold water for longer. So if heavy growth in tile interlocks (water channels) or in valleys and abutment gutters etc is likely to impede water flow then it is advisable to remove it. But it should be stressed that these growths are not necessarily deleterious to tiles and slates and can actually impart a mellow and pleasing appearance. In fact, older roofs are more often likely to have moss or lichen growth on simply because age has given the spores time to grow on the surface of the tile. The fact that such roofs have lasted so long would refute any spurious claims about tiles losing strength. Indeed tile manufacturers receive as many enquiries asking how to promote growth on the roof as they do asking how to remove it.

http://www.roofapedia.com/Roof-Info-Centre/3/Roof-Coatings.aspx

 

[tony1851]

I might be wrong here but I seem to recall reading some years ago that an acid produced by lichen can damage concrete tiles by causing pitting.

Perhaps that was the older type of tile.

 

[Birminghamroofer]

barnacles

 

[tony1851]

barnacles

 

[rjm2k]

I live in a 25yr old Permmison built 4 bedroom detached house whose roof is now looking sorry for itself.

I live in a 30yr old persimmon, the roof looks like a 30 year old roof and still works fine.

The roof doesn't leak and from ground level there does not appear to be any broken tiles (Marley Double Roman - identified via previous threads, thanks).

If it aint broke, don't fix it

Some of the plastic mesh which prevents birds accessing the roof space appears to be damaged/missing.

That's worth fixing to prevent birds getting into the roof

All the brown PVC guttering and downpipes have faded and need replacing.

Are you seriously considering replacing perfectly good gutters and downpipes because they have faded a bit? Were you in the property from new? If not, you will probably find you need to replace them every 5 years or so.

I do not wish to give the roofer free reign to check and offer to do work that may not be necessary.

Much of what you are thinking of doing is uneccessary

I don't want to revisit the roof for another 25yrs so will a simple request to clean, check and repair any loose tiles be sufficient?

If you change gutters and downpipes everytime they fade a little, expect to revisit every 5 years or so. The tiles will get dirty again, they live outdoors.

 

[^woody^]

Moss is generally cosmetic. There is a slight chance of risk of frost spalling where moss holds water, but even that is minimal risk in real terms

Moss will come back quicker and fresher after any cleaning attempt

A copper wire across the roof may help prevent it, but can lead to other staining

Best to just leave it, its a roof not a kitchen worktop