Buildup of moss and debris on slate roofs hold moisture in the slates that can split them during winter.
Slate roof discoloration.
You can also do a fair amount of checking at ground level.
Slate roof defect photo library.
White stains on slate roofs efflorescence or salt stains from rain water sometimes appear on slate shingles.
Slate is a beautiful and popular medium for fireplaces and patios but it is highly susceptible to stains from water and hard calcified deposited stains under pots and other items.
Also slate is slippery when wet.
Take a flashlight and check for water stains on the roof timbers especially after a long period of rain.
That ll prevent the cleaner from drying out too quickly.
You can spot a sloped slate roof tile more easily from the ground.
Pour it into a pump sprayer strap yourself into a full body harness tie it down and climb to the roof.
This slate roofing photo series shows all kinds of roofing slate defects.
Moss often grows in the shade of trees too.
Often the damage is hidden under overlapping slate courses and becomes apparent only when the roof starts to leak.
Regular roof cleaning is critical for your roof as slate is easy to cleave and water absorbent.
Historic slate roofs should be repaired rather than replaced whenever possible.
Before replacing a slate roof check for isolated damage corroded and worn flashings leaky gutters poor ventilation in the attic and other possible sources of moisture.
But there are other roof stain colors and causes.
If the tiles have water stains check for any hairline cracks.
Slate shingles do not lie flat against each other and can easily snap under pressure.
Before applying the cleaner spray the roof with water to cool it down.
Trees plant debris stains stain patches under trees or nearby may be due to seeds berries leaves and other debris falling and decaying.
If your slate is looking a little worse for wear do not be alarmed.
The remedies for and means of preventing stains on roof shingles are discussed as well.
You can t walk on a slate roof no matter how shallow its pitch.
When cleaning a slate roof don t use chemicals like ammonia or chlorine bleach.