# How do you clean a cedar shingle roof?



## Dorman Painting (May 2, 2006)

Pressure washing is the obvious thought, but I know it could potentially damage the roof. I've pressure washed hundreds of decks and such but never a shakes roof. this roof is in good shape but desperately needs cleaned. Once cleaned what should I seal it with??


----------



## Peladu (Jan 8, 2006)

What should you seal it with?

Are you asking for a particular Brand?


----------



## rws (Nov 26, 2004)

I have used a lot of roof grade cwf with good results but I think there are better new products around.The most important thing is to use a penetrating oil product vs a sealer. I used flood cleaner and a hose with a sweep nozzle and a scrub brush on the last one.P.I.T.A. But the roof was 15 years old


----------



## Humble Abode (Mar 19, 2005)

I would say JoMax, Bleach and dish detergent. Apply with a garden pump hose sprayer and let sit for 15 minutes, don't let it dry, continuously mist it.

Then power wash with low pressure, just the soap tip should do it.

Then, like rws said, use a penetrating semi-transparent oil base finish.


----------



## Dorman Painting (May 2, 2006)

Humble Abode said:


> I would say JoMax, Bleach and dish detergent. Apply with a garden pump hose sprayer and let sit for 15 minutes, don't let it dry, continuously mist it.
> 
> Then power wash with low pressure, just the soap tip should do it.
> 
> Then, like rws said, use a penetrating semi-transparent oil base finish.


So I can't use a pressure washer is basically what you're saying? I was thinking I could turn down the pressure and go with it. I'm aware that I can't shoot up on the roof or it would risk water getting under the shingles and possibly into the interior. 

Are you suggesting that I buy a strong cleaner and just hose off with a garden hose? I really don't understand what you're saying.


----------



## Squrtgun (Aug 27, 2006)

http://www.restore-a-deck.com/index.html

Give Ken a call.He can give you the particulars on his product.Bleach will work,but it's not the best solution.

Humble why add dish soap?Jomax is a surfactant(soap additive) for bleach and there is no need to add additional soap.


----------



## Brushslingers (Jul 28, 2006)

They are just saying use a bleach additive to make it thick enough to stay up there for a bit and then use your pressure washer on low pressure with the black tip to hose it down. Really depends on what exactly you are trying to get off... I mean is it mold and mildew or just dirty? But ya, that method is prolly the safest for a shake roof. Run a ladder (if you can) ON the roof, laying flat to the peak to stand on, don't kick one of those shakes off by stomping around on em.


----------



## Dorman Painting (May 2, 2006)

Brushslingers said:


> They are just saying use a bleach additive to make it thick enough to stay up there for a bit and then use your pressure washer on low pressure with the black tip to hose it down. Really depends on what exactly you are trying to get off... I mean is it mold and mildew or just dirty? But ya, that method is prolly the safest for a shake roof. Run a ladder (if you can) ON the roof, laying flat to the peak to stand on, don't kick one of those shakes off by stomping around on em.


This roof has lots of mold and mildew, it hasn't been washed in over ten years. I'm thinking there's noway around using some pressurized water, using a black tip would probably waste my time and energy IMO.


----------



## Brushslingers (Jul 28, 2006)

Dorman Painting said:


> This roof has lots of mold and mildew, it hasn't been washed in over ten years. I'm thinking there's noway around using some pressurized water, using a black tip would probably waste my time and energy IMO.


Good chemicals will solve it as long as the owner is cool, meaning... plants may or may not die, dog? etc... if it has that much mold and mildew though.... may want to crawl around up there and see how much rot there is, and then run away. Cedar shake roofs can get pricey.


----------



## Squrtgun (Aug 27, 2006)

I have heard of shake roof cleaning and sealing running as much as $30k.Of course price depnds on sq ft.


----------



## Grumpy (Oct 8, 2003)

Hmmm... Roofing questions in the painting forum. Someone explain that to me. One day will the painters realize there are other sections of this website other than painting?!


----------



## Grumpy (Oct 8, 2003)

You want to use a pressure washer with very high GPM but low PSI. YOu want the chemicals to do the washing, not the pressure. 

After you wash the roof, you should seal it. Thompsons won't accomplish crap. You need a specific cedar roof treatment like twp200. It's also available in colors. Are you insured for roofing work?


----------



## reveivl (May 29, 2005)

I've seen shake roofs leak after people have powerwashed them, be careful of that. Also, you probably are aware of this but I'll say it anyway, the roof when wet is unwalkable, if you step on it (without caulk boots:jester: ) you'll be on the ground sooner.

I watched two, one right after another, firemen step off a roof ladder onto a wetted shake roof that they were cutting into to get a fire in the attic, both fell and were saved by others lower on the ladder. Didn't give me much faith in the local fire dept. ("We've never lost a foundation!")


----------



## Grumpy (Oct 8, 2003)

Chicken ladders and scaffolds are usually the only way to clean most cedar roofs. Most cedar roofs are hard to walk on even when dry because they are steep, add water and you have a slip and slide and die.


----------



## MattCoops (Apr 7, 2006)

a wood roof
yucka
rip it all off
and slap some double lock copper on there


----------



## Joewho (Sep 20, 2006)

I've used deck brighteners and a good old deck brush/broom to cut through the mold and such.

A sealer specified for cedar will work. Cedar and redwood may not look good after time, but they ARE the woods that last a life time.


----------



## MattCoops (Apr 7, 2006)

wood on a roof???

rot
leaks
headaches

Copper is proper if you're willing to spend the dollar


----------



## Squrtgun (Aug 27, 2006)

Joewho said:


> I've used deck brighteners and a good old deck brush/broom to cut through the mold and such.
> 
> A sealer specified for cedar will work. Cedar and redwood may not look good after time, but they ARE the woods that last a life time.


Deck brighteners are not cleaning agents.They are designed to neutralize the PH after cleaning with a caustic and restore most of the original color.Oxalic or citric acids are the 2 common forms of wood brighteners.Sodium percarbonate will also do the trick,it's slightly more labor intensive but delivers nice results.

A caustic cleaner(sodium hydroxide)followed by an Oxalic bath will prove the best possible prep for the shakes to accept stain and give the stain longevity.


----------



## oacllc (Sep 20, 2006)

After proper cleaning I use the a Sikkens product. Akzo Nobel Coatings, inc.


----------



## RooferJim (Mar 6, 2006)

Cedar roofs should be left natural. around here when they get dirty they strip it "$" and do it again.

RooferJim


----------

