Concrete vs Masonry Retaining Wall Costs

[theCorkster]

A client is looking to place a pool in his backyard; to make the best situation, he is looking at terracing the yard and wants to use segmental walls for aesthetics.

The main retaining wall will also form the pool wall, and could either be masonry or concrete. Is/are there any design/construction/cost advantages to masonry over concrete in this application? What are typical costs per square foot for concrete and masonry retaining wall construction?

Thanks for the input!

 

[vandede427]

CONCRETE!



p.s. nice Excel drafting

 

[concretemasonry]

Your drawing shows a SEGMENTAL retaining wall made from interlocking blocks than cannot be used over a concrete footing or a concrete wall - That is a flexible wall, while a concrete wall is rigid.

For landscaping, segmental walls are preferred because of the lower cost, more natural appearance and ability to match the terrain and curvature economically.

For that 3' height, it is just a SRW gravity wall with no design and standard city design plates for municipal installations can be used. Normally, no engineering or geogrid until it is over 4 or 5 feet depending on the local code. - Much simpler than some of the 40'+ high walls that are engineered and built.

The need for possible fencing and post supports will also have to be addressed if the situation requires some sort of positive separation of the possible acess area and the pool 3' below.

 

[RHTPE]

CM is correct - know the local fencing requirements for a pool. Does his homeowner's insurance underwriter have any fencing requirements/recommendations for a pool as well?

Why not move the lower segmental wall off the concrete (to the left) to provide another planting terrace. Then you could install any required fence posts directly into the concrete wall.

I would never use masonry block construction for a retaining wall - cast-in-place concrete would be my only choice. But then, my thinking is influenced by where I live (New England).


Ralph
Structures Consulting
Northeast USA

 

[msquared48]

The lower wall needs to be concrete with a three foot earth surcharge applied too for the segmental wall above. The segmental wall to the rear appears back far enough so as to have little effect on the concrete retaining wall.

Mike McCann
MMC Engineering

 

[hokie66]

Nobody has attempted to answer your question about the relative costs of reinforced concrete and reinforced masonry walls, and I won't try either. This would depend a lot on typical practice in your area. I would not hesitate to use a reinforced masonry wall as a retaining wall in your situation, but not as the pool wall. The pool must have continuity through the floor to wall joint. What is the construction of the pool?

 

[mudflaps]

We used to design pools before our E&O carrier made us quit. Seems there were problems with contractors agreeing to build pools on hillsides, kind of like this one. In California, fully grouted masonry walls go for fourteen dollars per square foot - Union, before the economy collapsed. Non union would be less now days.

Still think a masonry pool wall would cost more than a shotcrete wall which is usually non-union. Remember, a normal concrete wall requires forming, a pool wall doesn't. Just dig the hole, put the rebar in and start blowing concrete and trowel to the finish desired.

Most pool contractors have details for "Special Condition" wall sections, like higher retaining walls. I suggest you have the pool contractor's engineer design all the pool walls and you handle the rest.

Old CA SE

 

[theCorkster]

Thanks for all of the responses. I appreciate the idea of moving the lower segmental wall away from the pool edge as it would reduce overall costs. The client is trying to come to grips with the cost versus aesthetics and this option was discussed before.



mudflaps; thanks for the perspective. I've worked on several projects involving pools on hillside/slopes, and only take them on when the owner is committed to what really needs to be done. I'll visit with the pool contractor further about this.

 

[InDepth]

Go concrete on the pool....usually pretty cheap using shotcrete between 4 and 5 inches thick.

Chekc out thes standard pool plans & retaining walls

http://www.pooleng.com/ca-27.aspx