Concrete – How to remove insulation fasteners from concrete

concreteinsulationremoval

I'm pulling a bunch of insulation from my basement to get ready to finish it, and have found it's bolted to the concrete walls. I've been able to google my way to identifying the bolts as Hilti X-SW 30 fasteners (https://www.hilti.com/direct-fastening/insulation-fastenings/r66753).

I managed to pry one out with a claw hammer, but naturally this damaged the surrounding concrete. I tried a second one and it managed to support all 200lbs of my bodyweight without budging.

So, I suppose I'm really asking two questions; How do I remove these things with minimal damage? And assuming some damage is unavoidable, what's the right way to plug the resulting holes and fix the damage?

If it's relevant, my plan after this is two coats of waterproofing paint, followed by XPS rigid foam insulation.

Best Answer

I would suggest a crowbar for removing them. The overall length of the crowbar body will determine the amount of force it's capable of producing. Obviously the fulcrum will be at the end against the wall where the head turns towards the fastener.

With a relatively long crowbar, your leverage will multiply significantly and they will come out much easier.

Basically - go to any home goods store and see how long of a crowbar you feel you could live with having around - the longer the better.

As for the damage to the cement - I'm stealing a page out of another website because it's well written:

Patching such holes is a necessary part of keeping your concrete foundation wall in good repair. If your aim is to make the wall look better, a smooth surface is also easier to paint. An ideal patch to use for both purposes is hydraulic cement, which expands to fill cracks and holes as it dries.

1 Remove loose material from the hole in the wall by probing it with the tip of a screwdriver or blade of a putty knife. Clean the hole and surrounding area with a wire brush. Vacuum any remaining dust or debris out of the hole.

2 Dampen the hole and surrounding area with water using a spray bottle.

3 Mix a small portion of hydraulic cement in a clean container according to package directions. Stir the cement with a putty knife until it has the consistency of thick peanut butter. Make only as much cement as you can use in three minutes or less.

4 Pack hydraulic cement firmly into the hole with a putty knife or trowel. Smooth the surface of the patch as quickly as possible before the cement sets.

5 Spray the patch lightgly with water several times over the next 24 hours. Allow the patch to cure for 48 hours before painting, or for as long as recommended by the manufacturer. Things You Will Need

Screwdriver
Putty knife
WIre brush
Wet/dry vacuum
Spray bottle filled with water
Hydraulic cement
Clean mixing container
Trowel (optional)

Tip

Unless the wall is well shaded, it's best to apply hydraulic cement early in the morning when the wall surface is cooler so the cement won't dry too quickly.

Warning

Wear rubber or latex gloves when working with hydraulic cement.

Those notes apply to an interior or exterior cement surface. With a proper putty knife technique you will have a very smooth surface ideal for painting.

Happy fixing!

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