Deck disasater - how to repair concrete posts?

[Andy]

I recently discovered a problem with my new deck's foundation and was hoping you folks might have some advice on how to proceed.

Last year, I built a conventional 22' x 14' x 2'high single level deck. I hired a local company to drill and fill with concrete the eight posts I required for the foundation.

This year, I noticed that 5 of the 8 posts are disintegrating. The concrete is was clearly not mixed correctly and can be easily broken apart with a screwdriver. The remaining three posts appear to be OK. The posts extend four feet under ground level and about 2 inches above ground level.

I am attempting to get the original company that drilled and set the posts to fix the problem, but what they are proposing doesn't sound like a solution to me. They want to put a layer of hydraulic cement around the tops of the post to prevent further decay.

I was wondering if anyone had any ideas on what could be done to salvage the project?

Thanks! Andy

[Edwin Pawlowski]

Their idea can work. It may feel crumbly on top, but you still have a 4' deep solid mass. Get more details as to exactly what they will do. I would think they'd want to dig down at least a few inches and pour a ring at least a few inches wider than the existing piers. See if you can get some guarantee against frost heaves due to the original improper installation.

You may also want to post this on alt.home.repair for more information. Ed

[Mark L.]

But what if the concrete was indeed mixed incorrectly? IMO, it will be crumbly

for the entire 4' length through the ground. It won't be a solid supporting mass at all.

I'm sure the concrete below the patch will deteriorate also. A fix? New posts in new concrete... Mark L.

[Edwin Pawlowski]

You mean like the stone foundations supporting 250 year old houses here in New England? Not a drop of cement, just packed stone.

[Buck Turgidson]

I don't think setting wood posts in concrete meets code in my area. You're supposed to sink a concrete pier below the frost line (4' here), and embed a bolt in the concrete. Then bolt a bracket on top of the concrete to accept the 4 or 6 by post. So no wood, PT or not, is ever below grade. Eventually it will rot below grade, PT or not.

[william kossack]

Sounds to me like your going to have to rebuild the deck unless you can pick the entire thing up, redo the concrete and then set it back place.

I was at a party a couple years ago where the house had a deck (young couple with kids with their new house). As the party progressed we noticed part of the deck started to bulge up in the middle. It turned out that all the posts were rotten except for a few where the bulges were. The owner ended up ripping out the deck completely because of poor construction and I hear he installed a rock garden/patio. Another friend is currently supporting his deck with a car jack(s).

If you rebuild make sure the wood is not set in concrete. It will last longer.

Andy wrote:

[BeniBoose]

It would be interesting to know why the concrete is disintegrating. As an architect, the only thing I can tell you is to get the work redone

100%. Patching it with another product will not prevent the concrete underneath to desintegrate. They're just hoping to buy some time and hide what will happen next. Add a few more cycles of frost/defrost and your concrete will become sand... and not support anything anymore. What you don't see doesn't hurt you... You paid for it, you deserve to get something in return...

In reminds me my own house after a water infiltration damage in the kitchen. I had a weak point on the roof and I must had a hundred liters of water that leaked in the exterior wall. The gypsum board bubbled everywhere... The insurance guy came and he was proposing to just "glaze" the walls and repaint. He was pretending the inside of the wall will dry and be just fine. I didn't accept his proposition and asked to have the whole wall torn down and redone. They accepted after I threated them to bring them to court. When I opened up the wall I had mold all over the place. Duh!

In your case, my best bet would be to have from now on everything in writing from everybody involved. Ask for a written proposal from the company who made the concrete post. Next, hire an independant consultant (architect, engineer, etc.) to get another "point of view". Compare and use that to force the company to do the correction or else... it will end up in court.

Good luck.

Ben

[xrongor]

you can probably just do them one at a time.

you can set PT wood posts in concrete just fine but you must do a few things. if the end of the post is encased in cement moisture will collect. its this standing water that pt cant hold up to. you want the cement more like a doughnut around it with the end sitting in gravel so water can simply drain away. so dig a little deeper, and make sure the last 2-3 inches of the post is entirely in gravel. it wont last forever, but it will last a very long time.

randy

[Andy Dingley]

That entirely depends on how severe your winters are.

Ah. That's not California is it ? You're going to have to replace them.

[Mark L.]

[J. Clarke]

Most of the stone used in construction in New England 250 years ago was basically disposing of the rocks that they dug out of the farm fields. If you go walking in the woods with any regularity you'll come across stone walls and the occasional hole in the ground that used to be a cellar, obviously long abandoned. The rocks are usually fairly sizeable--they only moved the ones big enough to present an obstacle to planting. If one wants to pile up a bunch of rocks to use as footings it should work fine if it's done right but that's not the same as bad concrete.