# Driveway/Sidewalk expansion joints



## dwycoff (May 25, 2004)

The original wood has rotted away leaving a gap where weeds can grow. Any ideas on the best way to repair?
Thanks in advance!


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## Aggie Chris (Jun 5, 2005)

http://askville.amazon.com/Question...-joint-wood/AnswerViewer.do?requestId=8708313


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## Jolly Roger (May 21, 2004)

Clean expansion joint out as best as possible, need at least 3/4" deep. Depending on how rotten the wood is, and how many feet of joint you have to seal if you need to replace the wood or just remove all the wood and seal the joint. If you have to replace the wood, use redwood. If you only have a few feet of joints, remove all the wood and seal the joints.

Go to a contractor supply house and get some SL1 or similar. Self leveling joint sealer. The same place will also have redwood.


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## jebatu (May 22, 2006)

I see you live in Pearland,
Call Sheplers in Houston they are on Almeda just south of 610 loop 713-799-1150 ask for Lanny get you some backer rod (closed cell foam) not real expensive and some NP-1 self leaveling sealer, tuck the foam in the joint (after you have cleaned it out as best you can) leave the foam about 1/4 low from top of concrete and fill with NP1. Come in tubes can apply with a regular caulk gun make sure concrete is dry so caulk will stick.


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## G-Money (Aug 3, 2007)

Take out as much wood as necessary, then fill the crack with "play sand" and grade the sand to a depth of 1/2" to 3/4" below top of sidewalk and pour in the caulk.


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## Jolly Roger (May 21, 2004)

G-Money said:


> Take out as much wood as necessary, then fill the crack with "play sand" and grade the sand to a depth of 1/2" to 3/4" below top of sidewalk and pour in the caulk.


do not want to use sand, it has a very low PI. When the concrete expands it will push the sand up, and blow out the joint seal.


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## Cat O' Lies (May 21, 2004)

Where can you buy the SL1 in a 1-5gal can? At $7 a tube, it gets expensive sealing a driveway and sidewalks


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## Jolly Roger (May 21, 2004)

Cat O' Lies said:


> Where can you buy the SL1 in a 1-5gal can? At $7 a tube, it gets expensive sealing a driveway and sidewalks


Do not think you are going to find SL1 in a can or bucket, could be wrong. Joint seals that we deal with that come in buckets are hot seals and have to be heated. SL1 is a cold joint seal and has to be forced out by a gun. If it is sold by the bucket should have it at a contractor supply house.

The tubes of SL1 we use are larger, for contractors and will do about 40' on top of redwood. Sidewalk and driveway joints are usually wider then the saw joints we seal on roadways. If the wood is rotten, try to replace it as best as possible. Baker rod will help, but will have to find someone that will cut a roll and sell it by the foot.

For home use you will want a smaller tube to fit in a regular size caulk gun. I do not know how much they will cover per tube.


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## Jolly Roger (May 21, 2004)

Cat O' Lies said:


> Where can you buy the SL1 in a 1-5gal can? At $7 a tube, it gets expensive sealing a driveway and sidewalks


here is a cheaper one

http://www.bestmaterials.com/detail.aspx?ID=16099

looks like they have SL2 by the gallon. I have enver used SL2, but sure it will work as good as SL1. Think the difference between the two is that SL2 has to be mixed, where as SL1 takes no mixing.

http://www.bestmaterials.com/SearchResult.aspx?CategoryID=969


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## StarlinMarlin (Aug 3, 2004)

Use a foam backer rod. Put the foam backer rod in the joint and then seal up the crack. This is very common way to seal expansion joints. This is also how vertical expansion joints in masonry veneer are sealed.


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## addison12 (Jun 26, 2015)

I purchased some myself. I was using hygrozyme and aquashield but still no real success to talk about. Hygrozyme is so expensive too! I am on my 2nd grow in a BCNL bloombox. Do you mind sharing how you grow with a newb?


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## Tortuga (May 21, 2004)

Whatever you're gonna use...use it NOW...with all this rain we have had..those slabs ARE gonna rise on you from the water going down in the expansion joints.. Don't ask how I know...grrrrr..$$$$$


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## fishingcacher (Mar 29, 2008)

StarlinMarlin said:


> Use a foam backer rod. Put the foam backer rod in the joint and then seal up the crack. This is very common way to seal expansion joints. This is also how vertical expansion joints in masonry veneer are sealed.


I saw some workers doing this very thing on an expansion joint in a commercial shopping center brick wall. Redwood will last forever. The house I grew up in had a redwood fence that is 60 years old. Just don;t get any splinters in your hands.


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## addison12 (Jun 26, 2015)

expansion joints are made out of what is called black board, or celotex, its availbe at most lumber stores, i would put an expansion joint every 10 ft. and at the step and drive, use 1/2 inch celotex, put it down pour the cement, add as nessary, and cut control joints every 3 or 4 f.


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## mirage (Jun 14, 2004)

I had this installed a little over a year ago. Looks good and has held up well so far.

http://trim-a-slab.com/


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## Aces Full (Aug 10, 2005)

StarlinMarlin said:


> Use a foam backer rod. Put the foam backer rod in the joint and then seal up the crack. This is very common way to seal expansion joints. This is also how vertical expansion joints in masonry veneer are sealed.


Starlin is correct. The backer rod is a necessity for longevity. It forces the self leveling caulk to be thicker at the edges where adhesion is needed and thinner in the middle where stretch is needed. They also have a primer that can be used on the concrete to help with adhesion.

If you don't use backer rod, expect it to split in the middle or tear away from either side.


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## fishinfool (Jun 30, 2004)

i have a joint in my driveway where two different contractors work starts and stops. the wood filler strip has the rebar ran through the wood, but the gap is large and not tight, my drive is sloped so water runs between the drive and the wood strip and under the drive. 

will this self leveling joint stuff work to fill my gaps, or do i need to put something under it. i am trying to stop the water from running under my driveway and washing out the dirt.


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