Fixing a pier to concrete

[Spookyer]

What is the relative value of embedding threaded rod in the concrete versus dynabolting or chem anchoring the pier after the concrete is set?

I would think the latter would be easier to do in terms of arranging and aligning the pier but would it be as strong?

Brett

[pmrid]

My answer is probably a reflection on my limited tool skills but there it is.

If you go the Dynabolt or chemical anchor route, you must first drill out suitably spaced and sized holes. In my past efforts, and despite my best care to the detail of this step, my holes have tended to wander off, lose vertical alignment and blow out in size. No doubt others will find drilling surgically precise holes in concrete a breeze. I don't.

Peter

[Tandum]

I used 12mm self tapping concrete bolts on mine, worked fine.

[mswhin63]

I am going to use a combination of both. I recently removed my concrete slab to my new place and during the de-installation one of the bolt concreted in broke. I will use self tappers to fix down the corner that broke.

In my time carry out installation of payphone we started to use Chemset on nearly all jobs, although after a period of time and testing we found the self tappers worked well for floor mounted installations. Instead of carrying the weight its job was only to hold down the product. Chemset was used extensively on wall mounted applications.

[cstocky]

I upgraded my observatory and pier last year. My original pier was anchored with bolts secured while I poured the concrete (a frame was used to ensure correct location while the concrete set). With the upgrade I had to cut out two of these bolts and add four new ones. The local Boltco shop recommended Chemset which is apparently very popular in the construction industry.

I drilled the holes through a template that matched the base of the pier into the concrete with a rotary hammer drill. I sweated over ensuring that all was square. The Chemset was really easy to use with care needed to make sure that everything was clean and completely free of concrete dust afterwards. The bolts are within +/-0.5mm of my desired location. I'm very happy with the result and the pier is extremely solid.

If you do go down this path, a rotary hammer drill makes life significantly easier, much better than a regular hammer drill. Like a hot knife into butter :).

Regards,
Chris

[mswhin63]

Totally agree, I usually use a Hilti Drill for concrete drilling. One day I left it behind :rolleyes: and had to use my regular drill, Job took 3 time longer and burn't out one of my drills in the process.

Have never left it behind since :D

[ZeroID]

Rockite ...
Used in the building industry to secure safety railings into drilled concrete. Non shrink, non expand, sets like rock. I've used it to cast amateur rocket nozzles, no problem.

[traveller]

Getting back to the original post, I bolted 12mm threaded rods through a 400x400 mm concrete pad, then bent the ends to make a "claw".
I plan to do th concrete pour tomorrow 12x20kg of pre mix, a relatively light pier.