Can a experienced mason please tell me what happens when you put type N masonry cement in a 18 inch diameter sonotube that sets 3 feet below grade. I had a argument with a guy who i work with who is a mason or as he calls himself, I am the masonry. Anyway, I am a carpenter with 6 years in the trade, and i went to set my post and anchor set on top of this pier that was poured previously by my co-worker the mason. I was attaching the post/anchor kit to this pier, and my shield and lag wouldnt take, just kept spinning in the hole that i drilled into the top of the pier. I am building a deck and was trying to attach my 6x6 posts to these piers. Anyway, I found out that he used the same cement type n that he used to do the stucco on the exterior of pool house that the deck attaches to. I did some research and found out that he should of used type m since it was for below grade for these piers. Well, did this set off a fire storm/ argument. Anyway can someone tell me what will happen to these piers that he used type n cement in?

 

The Type N is probably a masonry cement, which should never be used in concrete. It is used to lay brick and block.

Type M is also masonry cement that should not be used in concrete. It is also used to lay brick and block.

For concrete, you should use Type I Portland cement and mix it with sand and rock. An alternate for a small quantity, would be premixed Sakrete or Quikrete CONCRETE mix that already has the sand and rock in it.

Dick

 

I told the guy i work with that he should be using concrete, to fill the sonotubes, However, his response was that he been doing this for 30 years....blah blah. He did mix some crushed stone and sand with type N masonry cement and he did have rebar in the tubes. So in short he should have used concrete, instead of cement. Could you also tell me what might happen to the piers that were filled with type N cement?? Will they just crumble away over time? I mentioned to my supervisor that he used the wrong stuff, and my supervisor had him fill the hole around the sonotube with acecrete. I guess a brand of concrete. With this help.. ???

 

Send him:

Masonry in practice: Mortar Types | Portland Cement Association (PCA)

Cement Types Be safe, GBR

 

Your contractor is an ignorant "hack".

Types N & M are for mortar and have the properties desired for masonry construction (block and brick). Concrete construction is really not masonry, but it is commonly dumped into that category by people that are not familiar with it.

For mortar, it is suggested to use lowest strength possible to get the other more desirable properties (workmanship, bond, etc.), since strength is not important for mortar.

By adding sand and rock to the wrong type mix, he lowered the strength and durability of the material he dumped in the Sonotube.

Usually strength of the concrete in a Sonotube, supporting a deck is not critical. but it could be. He probably had no trouble drilling the holes for the anchors, but they spun because they could not get a "bite" into the soft "concrete".

If you cannot get the anchors to hold, you do not get the necessary connection between the concrete and connector for the post.

Dumping some concrete around the Sonotube will do nothing to improve the connection between the concrete tube and the post. I suggest you get the sonotube out and replace with something proper. A risky alternate would be to try and find an epoxy to anchor the connector anchors and cross your fingers. Even if you get a solid anchor, the "concrete" could break out later when the right/wrong loads occur.

Were you lucky enough to have an inspector around?

 

The inspector came and inspected the depths of the two holes! However, the funniest thing happened, the mason had just completed the last coat/finish of "stucco" to the pool house a couple of days previous. The inspector came for our rough-in framing for the interior framing that was completed, asked my supervisor, "Are you going to stucco this"? My supervisor had this look on his face like come again.... Haha i laughed so hard... even the inspector had a hard time realizing that the stucco was a finish coat, looked like a really bad scratch coat. Work is very comedic for me, working with this putz...thanks for your responses to my post....