concrete in wetlands
	Post Reply		Forum

Posted by: gBrody ® 09/19/2006, 10:42:48 Author Profile eMail author Edit

Hello, We are building a small staircase from our deck. 42" wide and 7' high. 7" rise and 11" treads. We live in a wetland and the town code calls for 32" deep concrete pour for our 6 x 6 supports. The problem is about 12" down the hole we dug for the 12" sonitube is filled with water. What do we do with concrete in this case or is there another way to support the 6 x 6 post? Thank you so much for any help.

Replies to this message

Re: concrete in wetlands
Re: concrete in wetlands -- gBrody	Post Reply	Top of thread	Forum

Posted by: Guttdogg ® 09/19/2006, 11:44:40 Author Profile eMail author Edit

Pump it out... otherwise, pour it full of concrete... It will displace the water, just take longer to set.

Post Reply Tell a Friend (must be logged in) Alert Admin About Post

Where am I? Original Top of thread

| |

Re: Re: concrete in wetlands
Re: Re: concrete in wetlands -- Guttdogg	Post Reply	Top of thread	Forum

Posted by: Kelly Bramble ® 09/19/2006, 11:50:27 Author Profile eMail author Edit

If you are buying the concrete yourself from your favorite hardware place, I would buy the quickcrete brand. You can actualy pour it in without first mixing with water. The ground water will seep in and cure the concrete. Just do the foundation area this way, then mix and pour the cosmetic areas yourself.

Post Reply Tell a Friend (must be logged in) Alert Admin About Post

Where am I? Original Top of thread

| |

Re: Re: Re: concrete in wetlands
Re: Re: Re: concrete in wetlands -- Kelly Bramble	Post Reply	Top of thread	Forum

Posted by: Guttdogg ® 09/19/2006, 12:06:43 Author Profile eMail author Edit

Good thought Kelly... But make sure when you do this, to pour it in slow enough so you dont have clumps of dry mix in the middle. Not that it would cause huge problems, but it weakens the integrity of the concrete.

Post Reply Tell a Friend (must be logged in) Alert Admin About Post

Where am I? Original Top of thread

| |

Re: Re: Re: Re: concrete in wetlands
Re: Re: Re: Re: concrete in wetlands -- Guttdogg	Post Reply	Top of thread	Forum

Posted by: swearingen ® 09/19/2006, 13:58:24 Author Profile eMail author Edit

To get the most strength out of your concrete, it's very important that it be mixed with the right amount of water. I suggest that you mix your concrete first and then tremie it into the hole. To do this, use a piece of 4" or 6" diameter pipe (HDPE is fine). Put the pipe in your 12" hole all the way to the bottom. Pour your concrete in the pipe (use a funnel if needed) and it will displace the water from the bottom up. This prevents the aggregate from coming out of the concrete and greatly reducing the strength. If you just poured the concrete in the hole, the standing water would effectively wash the aggregate clean and the aggregate would fall to the bottom while the cement powder slowly settled on top. This reduces strength and also increases the likelyhood of spalling on the surface. Also, contrary to the above statement, the concrete will cure quicker under water. Concrete does not have to "dry". It actually uses the water molecules in the chemical reaction - it needs the water to cure.

Post Reply Tell a Friend (must be logged in) Alert Admin About Post

Where am I? Original Top of thread

| |

Re: Re: Re: Re: Re: concrete in wetlands
Re: Re: Re: Re: Re: concrete in wetlands -- swearingen	Post Reply	Top of thread	Forum

Posted by: gBrody ® 09/25/2006, 10:18:23 Author Profile eMail author Edit

Thank you for all the good advice. I thought one more description to be sure I made my situation clear. Our 32" deep by 12" wide hole is completely filled with brackish bay water. It would be as if we were pouring concrete into a long bucket filled with water. The water isn't seeping in, it is just there. Will the tremie technique work in this situation? Thanks you all.

Post Reply Tell a Friend (must be logged in) Alert Admin About Post

Where am I? Original Top of thread