Replies

1. 
   jc21 | Jun 07, 2006 02:28pm | #1

   Pressure wash? ....................no way- imho it's just too easy to damage the shingles. 2500 psi will at the very least blow the granules off if not blow a hole through the shingle. Can't tell from the pic but I assume you have a mold/mildew/lichen problem of some sort on the roof. You might try a bleach/TSP solution in a garden hose sprayer. Test a small section first. Spray on and rinse off. With the sprayer you shouldn't have get on the roof.

1. 
   HARDWOODGUY | Jun 07, 2006 03:18pm | #2

   That sounds much easier! Yes, mold and mildew.

1. 
   MikeSmith | Jun 07, 2006 05:10pm | #3

   no pressure washing..

    get some copper strips and slip them under the ridge shingle caps..

    the copper will leach out and take all the mold & mildew whenever it  rainsMike Smith Rhode Island : Design / Build / Repair / Restore

1. 
   txlandlord | Jun 07, 2006 07:37pm | #4

   We have been using SG (stain guard) or SR (stain resistant) shingles from the manufacturer, without problems.

   I seem to remember a manufacturer producing a zinc strip applied in the same way you suggest. Am I dreaming or confused, or do zinc strips also work in preventing or reducing staining from mold and mildew?  

1. 
   intrepidcat | Jun 07, 2006 10:57pm | #6

   Zinc usually always keeps the mold/ mildew away. I could never understand why it's not used more.

    

     

   If having a low wage work force was good for a country's economy then why hasn't Mexico built a fence? 

    

2. 
   MikeSmith | Jun 08, 2006 12:06am | #8

   i used to use zinc also.. but  one of the wood gurus on this  forum pointed out that copper is cheaper, easier to work with, and more effective

   if you read the labels of the Algae resistant shingles you will see they are adding copper..... not zincMike Smith Rhode Island : Design / Build / Repair / Restore

3. 
   HARDWOODGUY | Jun 08, 2006 12:42am | #9

   Thanks Mike!

    

   "get some copper strips and slip them under the ridge shingle caps.."

    

   Slide them in under at the top? 3-4 inches wide? Does it matter? Oh okay..caps..meaning the top..doh!

4. 
   MikeSmith | Jun 08, 2006 01:13am | #10

   like a 3"  by 3 ft. strip... roll the bottom edge up a little  ( say  1/8" ) to make a mini-dam

   slip about 2" under the first course below the caps and nail it with copper nails.. you can blind nail it  ( lift the shingle )

   or face nail it and put some roofing tar over the nailMike Smith Rhode Island : Design / Build / Repair / Restore

5. 
   HARDWOODGUY | Jun 08, 2006 03:35am | #11

   Oh, so it remains permanent. Nice. I wonder how long it will take to show improvement? This area gets 5 inches rain a month.

6. 
   BillHartmann | Jun 08, 2006 04:47am | #12

   Tin oixde and copper oxide or both very common anti fungals.Look at the Jasco products and you will find both.Boat anti fungal uses tin oxide. IIRC there used to be copper based paints, but it was restricted.

7. 
   Stray | Jun 08, 2006 06:00pm | #13

   I'm curious if the tin is less prone to leaving stains on the roofing (ie green from the CU)?  That'd be worth a little more for the tin IMHO.

   I was planning on using one of these on my own reroof this fall.  Have you noticed any green stains on the copper strips in place for 5+ yrs?Ithaca, NY  "10 square miles, surrounded by reality"

8. 
   MikeSmith | Jun 08, 2006 10:17pm | #14

   stray.. i don't have any strips on my roof.. but a 3" strip is not going to leave much of a trailMike Smith Rhode Island : Design / Build / Repair / Restore

9. 
   intrepidcat | Jun 09, 2006 12:13am | #15

   Copper probably looks better, too.

     

   If having a low wage work force was good for a country's economy then why hasn't Mexico built a fence? 

    

2. 
   intrepidcat | Jun 07, 2006 10:55pm | #5

   I was gonna say zinc. Wonder why zinc strips aren't placed on more roofs when shingles are installed?  Cost? Is it that much?

    

     

   If having a low wage work force was good for a country's economy then why hasn't Mexico built a fence? 

    

2. 
   RenaissanceRestorations | Jun 07, 2006 11:54pm | #7

   2nd vote on the no pressure washing scenario. My neighbor, recently retired, and with tons of time on his hands, bought a pressure washer and spent the better part of 2 weeks washing his roof. It now has some
   nice circle and swirl patterns as a result....

   Renaissance Restorations LLC
   Victorian Home Restoration Services

   http://www.renaissancerestorations.com

3. 
   florida | Jun 09, 2006 12:42am | #16

   Get a samll container of granulated pool chlorine. Mix about a cup in 2 gallons of hot water and mix until it's dissolved. Use the chemical injector and tip that comes wiht the pressure washer and spray the chlorine mixture from the ground or a ladder. Soak the roof well and let it dry. If one treatment doesn't do it do it again. Rinse and pants under the drip line when you're done. It's cheap, it's fast, it's easy and it works like a charm.

   Forget zinc or copper strips. They only work about a foot downhill and not very well even there.

1. 
   MikeSmith | Jun 09, 2006 01:31am | #17

   florida guy.. great idea.. for fixing it after the algae & mildew are already there..

    but you're wrong , wrong, wrong  about the strips not working... they work fine and they work for the whole roof

   remember when ridge vent was made of metal ?

   one of the options was to buy them in  copper or zinc... either one worked great in preventing algae

   copper strips are a prevention .. and a long term cure.. they won't remove the algae overnite like your method will.. but they will over a year's timeMike Smith Rhode Island : Design / Build / Repair / Restore

2. 
   seeyou | Jun 09, 2006 02:27am | #18

   >>>>>>>>>>>Forget zinc or copper strips. They only work about a foot downhill and not very well even there.May be a regional situation. In Ky, nothing grows straight downhill from any galvanized, terne, lead, or copper flashing. It's not unusual to see a roof completely covered with algae except for a strip from the waste vent all the way to the eave. 

   Does this hat make my butt look big?

   http://grantlogan.net/

1. 
   donpapenburg | Jun 09, 2006 04:35am | #19

   Some wizzards at the IDOT let a contract for several Thousand dollars  for their BIL to pressure wash the saltdome roofs  that were asphalt shingled.  It was a test to see if they could fleece the taxpay..........er I mean to see if the roofs would last longer.