Deadman or thrust block, what’s the difference?

Sunday Signal

By Robert Lamoureux, Signal Contributing Writer

What is the difference between a Deadman and thrust block or are they the same? 

— Gary M. 

Dear Gary,

A Deadman is put under a piece of horizontal pipe and is molded together with all thread and Unistrut, from the bottom. You dig a hole under a piece of pipe that you’ve repaired and put a large block of concrete, could be as much as 1500 lbs, into the hole with all threads sticking out of the concrete above the pipe. We then put Unistrut, (metal bar) two pieces which is 4 bolts, and we bolt that down so that the pipe is secured in place and unable to rise in an upwards motion. 

A thrust block is for horizontal movement, often used with domestic and irrigation pipes. This also, is a block of concrete that is put at a 90 degree turn, where the end could possibly blow off. A perfect example is a main fire line; there should be a thrust block at any turn, to prevent the pressure from allowing the pipe to come apart. If the thrust block is not installed, the pressure can eventually allow the pipe to come apart and leak. The leak erodes the soil, leaving a cavity which then allows the pipe to move more and cause the connection to come apart, creating in some cases, catastrophic damages. 

Concrete walkway work


We have a concrete walkway that needs power washing and re-painting (staining?). Picture attached. In your last column you mentioned that you have a reference for a reputable company that sounds like the kind of company we need. Would you send us the name? Thank you. We appreciate your help. 

— Kathy S. 


Kathy, from the photos it appears that the paint is spalling and now cannot be stained. You’ll need to go back with surface exterior concrete paint. I will send you the reference I have, he’ll take good care of this for you. Good luck. 

Mailbox pedestal height

Hi Robert,

I am a Property Manager here in Santa Clarita. One of my communities installed cluster mailboxes, but I need to know if there is a way to reduce the height of a mailbox pedestal. I have an elderly lady who is unable to stand up straight, limiting her reach, and she can’t access her mailbox. Please let me know if this is possible, and if you have any ideas. 

— Lisa H. 


Great question, thank you for writing in. Unfortunately, you cannot alter the height of the mailboxes, per USPS requirements. They have very strict standards for the height. The best thing might be to ask her to switch with someone who has a lower box than hers. Good luck

Robert Lamoureux has 38 years of experience as a general contractor, with separate licenses in electrical and plumbing contracting. He owns IMS Construction Inc. in Valencia. His opinions are his own, not necessarily those of The Signal. Opinions expressed in this column are not meant to replace the recommendations of a qualified contractor after that contractor has made a thorough visual inspection. Email questions to Robert at 

[email protected].

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