Setting posts atop existing concrete patio...anchor?

[rbstern]

I'm going to build a lean-to off the back of an existing house. The house has a concrete patio which exceeds the footprint dimensions of the lean-to, so the posts will be atop the concrete.

The question: Do these posts need to be anchored?

 

[grsthegreat]

Yes. Otherwise if they get bumped they will move.

 

[Roadworthy]

I would definitely secure the base of the post to the concrete. I like to use a steel spacer to separate the wood from the concrete - it's even code in some places. The spacer may then be anchored to the concrete with"Ramset" or something similar. I drill a hole to set the anchor then add a bolt. I prefer this system to driving in a stud leaving a threaded end sticking up.

 

[i7win7]

Big box lumberyard should have something like these

SPACEEUP Post Base 4"x4" Post Anchor 1pcs Adjustable Post Base Stainless Steel Concrete Post Anchor for Pavilion Deck Railing Support Decorative Anchor Plate: Amazon.com: Tools & Home Improvement

SPACEEUP Post Base 4"x4" Post Anchor 1pcs Adjustable Post Base Stainless Steel Concrete Post Anchor for Pavilion Deck Railing Support Decorative Anchor Plate: Amazon.com: Tools & Home Improvement

www.amazon.com

https://www.amazon.com/Simpson-Strong-FPBB44-Powder-Coated-12-Gauge/dp/B0026T7AZG/ref=sr_1_66?adgrpid=1344703295359341&dchild=1&hvadid=84044028259591&hvbmt=be&hvdev=c&hvlocphy=83764&hvnetw=o&hvqmt=e&hvtargid=kwd-84044324033910%3Aloc-190&hydadcr=7547_10458228&keywords=anchor+post&qid=1633448618&sr=8-66

I prefer the 1st 1, only 1 hole to drill per post

 

[ljjhouser]

The Simpson Strong Tie looks stronger and might be anchored using Tapcons - and washers if needed.

 

[rbstern]

Okay. Anchored it is. Thanks for the feedback!

 

[ljjhouser]

Good. I would not want to under estimate the power of wind gusts during a short thunderstorm. Might make the roof or shed sail.

 

[Frankenkubota]

Big box lumberyard should have something like these

SPACEEUP Post Base 4"x4" Post Anchor 1pcs Adjustable Post Base Stainless Steel Concrete Post Anchor for Pavilion Deck Railing Support Decorative Anchor Plate: Amazon.com: Tools & Home Improvement

SPACEEUP Post Base 4"x4" Post Anchor 1pcs Adjustable Post Base Stainless Steel Concrete Post Anchor for Pavilion Deck Railing Support Decorative Anchor Plate: Amazon.com: Tools & Home Improvement

www.amazon.com

https://www.amazon.com/Simpson-Strong-FPBB44-Powder-Coated-12-Gauge/dp/B0026T7AZG/ref=sr_1_66?adgrpid=1344703295359341&dchild=1&hvadid=84044028259591&hvbmt=be&hvdev=c&hvlocphy=83764&hvnetw=o&hvqmt=e&hvtargid=kwd-84044324033910%3Aloc-190&hydadcr=7547_10458228&keywords=anchor+post&qid=1633448618&sr=8-66

I prefer the 1st 1, only 1 hole to drill per post

just finished building new house.

i have 5 posts sitting on concrete slabs. the product described in the first link is what we used.

 

[Dave M7040]

Don't forget the wind uplift forces which is a big reason to have the posts well tied to the concrete.

In deciding what fastener to use, consider the diameter. A Tapcon screw will be strong to start with but add a bit of corrosion and soon the cross section of the screw is significantly reduced. Corrode 1 mm around the screw and its strength is greatly reduced. Corrode 1 mm around a 1/2" diameter anchor and you have decades of strong performance left.

Fewer large diameter fasteners provide long term performance.

Dave M7040

 

[Lineman North Florida]

I have a feeling that due to uplift that they are engineered to be used with 1/2 anchor bolts , you can jury rig lots of things to make them work, but it probably won't have the true strength that it was tested and engineered for.