Concrete repair resistance

[anonymous1]

10 drill holes (8mm diameter, 50 mm length) in a concrete ceiling were filled using a high strength concrete repair product and a bonding agent. It’s been curing for a whole year. What are the chances of drilling in the repaired area is secure to hang a curtain pole max 20 kg weight? Since the surface is painted is not possible to determine where the old holes were

 

[AC Power]

I would certainly think it would be fine, and in my trade, we drill in concrete hanging transformers weighing well over 20kg (44lb). To be sure, use long wedge anchors.

If your previously filled holes were 50mm (2") deep, then 3" or 4" long wedge anchors will work. The width of the anchor would be 1/4".

VERY IMPORTANT NOTE #1: When your hammer drilling your holes, your drill bit should be EXACTLY width of hammer drill as the width of the anchor. If you choose to 1/4" wide anchors, then USE a 1/4" SDS hammer drill bit. DO NOT DEVIATE!!!

VERY IMPORTANT NOTE #2: When you drill the holes, drill them the entire depth of the wedge anchor. So, if your wedge anchor is 4" long, then drill the WHOLE 4" in depth.

VERY IMPORTANT NOTE #3: When your about to hammer the wedge anchor in, leave about 1/2" hanging out!! Do not hammer the anchor ALL the way in. Place your curtain hanger hardware over the exposed threads, and hand-thumb the nut/washers on. Then when you begin to torque the nuts down with a wrench, the anchor will begin to pull out. Don't worry.....as you torque more-and-more, the wedge anchor will resist more-and-more. Once it feels very snug, stop.....DONE.

Hope this helps.

 

[anonymous1]

I would certainly think it would be fine, and in my trade, we drill in concrete hanging transformers weighing well over 20kg (44lb). To be sure, use long wedge anchors.

If your previously filled holes were 50mm (2") deep, then 3" or 4" long wedge anchors will work. The width of the anchor would be 1/4".

VERY IMPORTANT NOTE #1: When your hammer drilling your holes, your drill bit should be EXACTLY width of hammer drill as the width of the anchor. If you choose to 1/4" wide anchors, then USE a 1/4" SDS hammer drill bit. DO NOT DEVIATE!!!

VERY IMPORTANT NOTE #2: When you drill the holes, drill them the entire depth of the wedge anchor. So, if your wedge anchor is 4" long, then drill the WHOLE 4" in depth.

VERY IMPORTANT NOTE #3: When your about to hammer the wedge anchor in, leave about 1/2" hanging out!! Do not hammer the anchor ALL the way in. Place your curtain hanger hardware over the exposed threads, and hand-thumb the nut/washers on. Then when you begin to torque the nuts down with a wrench, the anchor will begin to pull out. Don't worry.....as you torque more-and-more, the wedge anchor will resist more-and-more. Once it feels very snug, stop.....DONE.

Hope this helps.

View attachment 5630

Thanks so much for a very complete answer.

Have you tried actually filling and redrilling?

 

[AC Power]

Yes. If a commercial concrete filler (2-part epoxy bonding agent) was used, a hammer drill will have no problem going through it, and a wedge anchor that follows does hold. It's when a cheap home-hardware grout (no bonding agent) is used that the process ends up crumbling and falling apart.

You'll be ok.....just make sure you follow the three (3) important points above. I've been in business for years now, and seen too many employees incorrectly install these. If their done right, they work VERY well.

Good Luck.

 

[anonymous1]

Yes. If a commercial concrete filler (2-part epoxy bonding agent) was used, a hammer drill will have no problem going through it, and a wedge anchor that follows does hold. It's when a cheap home-hardware grout (no bonding agent) is used that the process ends up crumbling and falling apart.

You'll be ok.....just make sure you follow the three (3) important points above. I've been in business for years now, and seen too many employees incorrectly install these. If their done right, they work VERY well.

Good Luck.

Thanks so much for your feedback. Sika products were used. Top of the tops for both concrete repair compound and bonding agent.

 

[AC Power]

Your Welcome. Sika is known to be good quality.