Front walk repair - do you have a better idea how to do this?

[tomtheelder2020]

The front walk at my MIL's house had decorative 2x4 strips at shrinkage control joints (see photos). Several need to be replaced. These were only about 1! thick set down into the concrete (i.e. concrete continuous beneath them) and held in place by nails extending from the boards into the concrete. The boards are long gone. Measuring the gaps, there is little consistency in width or depth of the boards. That is ok; cutting them to unique sizes will take some time but won't be difficult. to fit them in I will have to use my oscillating tool to cut off the old nails.

The issue is - how to hold the new wood pieces in place? My guess (and it is only that) is construction adhesive would not hold them very long. Holding them in place with screws set into concrete anchors seems like overkill. The best idea I can come up with is to: 1) cut the wood to about half the original thickness; 2) set several screws along the length of the bottom, extending about 1/4 inch below the bottom; and 3) set the board down into a thin (about 1/4 to 1/2 inch) layer of mortar in the bottom of each gap. When the mortar sets the screw heads should hold down the boards. That is a pretty skimpy layer of mortar but I can't think of anything that would pull up on the boards. I live in the Sacramento Valley so freezing is not an issue.

What do you think? Anyone have another idea? Thanks.

 

[Snoonyb]

Forget all that milling,I'd use SIKABOND.

 

[Steve123]

+1 on don't use wood. It will rot away.

Use a grey polyurethane masonry caulk. Put down painters tape on the top of the adjacent slabs to minimize possibility of getting caulk on top of the sidewalk slabs.

 

[PJB12]

Tremco makes a self leveling urethane sealant line named Vulkem.

The Vulkem 116 Self Leveling is good for this application. It comes sanded for the masonry look or unsanded for a glossy finish. It's available in a wide variety of colors. You can pick a close color, or a far different color for contrast.

With a level, figure out which end is lower of the joint. Put a temporary dam there. A plug of Duct Seal works very well. (Mud or wadded up wet cardboard do too, in a pinch.)

From the high end, squeeze some self-leveling into the joint and it'll flow to the dam. You'll end up with a smooth and even fill. No tooling is needed.

Vulkem 116 self-leveling holds on tenaciously and lasts about forever. One note is that the lighter colors may darken with dirt tracked over some years. The product bleaches back lighter well.

Or, if you prefer, 116 also comes in gun grade that handles like any ordinary caulk. (Not self-leveling. no dam needed)


Their 45SSL is semi-self leveling. If you prefer a coved finish or a crown, this will be the choice to use. This one only comes in 5 colors. Grey, Limestone, Black, Buff and White, which doesn't stay white long.



Paul

 

[opplumbinghubks]

The front walk at my MIL's house had decorative 2x4 strips at shrinkage control joints (see photos). Several need to be replaced. These were only about 1! thick set down into the concrete (i.e. concrete continuous beneath them) and held in place by nails extending from the boards into the concrete. The boards are long gone. Measuring the gaps, there is little consistency in width or depth of the boards. That is ok; cutting them to unique sizes will take some time but won't be difficult. to fit them in I will have to use my oscillating tool to cut off the old nails.

The issue is - how to hold the new wood pieces in place? My guess (and it is only that) is construction adhesive would not hold them very long. Holding them in place with screws set into concrete anchors seems like overkill. The best idea I can come up with is to: 1) cut the wood to about half the original thickness; 2) set several screws along the length of the bottom, extending about 1/4 inch below the bottom; and 3) set the board down into a thin (about 1/4 to 1/2 inch) layer of mortar in the bottom of each gap. When the mortar sets the screw heads should hold down the boards. That is a pretty skimpy layer of mortar but I can't think of anything that would pull up on the boards. I live in the Sacramento Valley so freezing is not an issue.

What do you think? Anyone have another idea? Thanks.

Your idea to use screws in mortar to secure the wood strips should work, but there are easier ways to make it last longer. Treat the wood to protect it from the weather, and use a strong adhesive like Sikaflex, which sticks well to concrete. You could also use nails into the sides of the concrete, like the original method. For a simpler option, try epoxy or a backer rod with sealant, which would hold the wood in place while allowing a bit of movement. These approaches could make the job easier and last longer.

 

[tomtheelder2020]

Snoonyb, Steve & Paul,

Thanks for the suggestions but I don't think the urethane products will work for me. These gaps average about 1.5" x 1.5" which is more than the manufacturers recommend. Also, we are preparing the home for sale and I don't think the urethane will look as good a wood, particularly fewer than half the wood strips need to be replaced after almost 40 years (redwood is good stuff). Finally, and most importantly, my wife doesn't like the idea. I will likely use screws through the wood anchored in the underlying concrete.

 

[tomtheelder2020]

Your idea to use screws in mortar to secure the wood strips should work, but there are easier ways to make it last longer. Treat the wood to protect it from the weather, and use a strong adhesive like Sikaflex, which sticks well to concrete. You could also use nails into the sides of the concrete, like the original method. For a simpler option, try epoxy or a backer rod with sealant, which would hold the wood in place while allowing a bit of movement. These approaches could make the job easier and last longer.

Thanks for the suggestion. My original idea of screws into wet mortar was not my best moment. My revised idea was to just screws through the wood into anchors in the concrete. I was skeptical of construction adhesive to hold the wood in place but your comment and the others are convincing me. Thanks.