My wall is bigger than Trump's wall...Part 1

After about 1.5 years of renovating the house (I added a cedar covered porch in the back, expanded a single car garage to a two car garage in the front and worked on  the boat house) while holding a full time job I found myself at the point where I needed to work on landscaping.  Since I live by a canal which connects to the sensitive banana river I am required by the department of natural resources to build a swail.

A swail is a shallow depression and in my case it is about 5 feet wide 60 feet long and 3" deep.  Because of the additional square footage, there is the concern that the runoff from the roof will go into the river.  The swail helps capture the runoff before it goes into the river so that the water is filtered by the sand before it enters the canal.

However, there is  steep slope in the yard due to the fact that the house is about 5 feet above the water level in the canal and the house only sits 20 feet away from the water.   Because of this the swail becomes ridiculously deep on the house side in order for it to have a level base. 

Another problem that I as well as many other homeowners around the area have is that the seawall is made of corrugated sheet material that allows dirt to pass through its seams.  Over time this results in a watery trench behind the wall.  Its a tripping hazard and the steep slope near the seawall doesn't help.

Many home owners in the neighborhood have put in new vinyl seawalls that are as much as three feet higher than the old seawall.   The u shaped vinyl pieces are placed in the water and sunk down into the sand with a jet pump.  The vinyl is then capped off at the top and the wall is anchored to the land by using tie bars attached to cement pads located 12' from the seawall buried in the sand.  The cement pad and tie bar combination is known as a dead man.  Then fill dirt is placed behind the new wall and the old wall is covered up.  The end result is very nice and seems very durable.  The only problem is the water becomes somewhat inaccessible due to the seawalls new height.  But the homeowners are prepared for global warming!  The price of such an installation is $210 per linear foot or about $16,800 for the 80' of seawall I have.  I think those professionals should work a step into the design to allow easier access to the water.

Below is an example of some typical seawalls used to replace the 70 year old corrugated asbestos seawall that was originally put in the neighborhood.  The one on the left uses pressure treated wood and the other uses vinyl sheets.  Note the height of the vinyl seawall.

My seawall seemed fine even though it was 70 years old.  There was a 5 foot long horizontal crack in one section of the seawall and the seawall was tilting out at the bottom about 6 inches but even so it was good for another 50 years.  However it did leak sand.  One method that is commonly used around here to fix the leak is to use filter cloth.  This black plastic holey cloth lets water pass but not sand.  The idea is to dig a trench behind the seawall and run a 6 foot wide filter cloth sheet all the way along the 80' of seawall and then back fill with sand  Theoretically the idea should work.  However, for one reason or another the filter cloth over time slips down into the ground and you end up with the same leaky sand problem.  For my seawall this was done about 15 years ago.

When sand leaks out in one spot around the seawall a common method for a quick fix is to throw bags of dry cement in the hole.   This theoretically should work and the cement should harden an plug the leak.   I personally unloaded several bags of cement in the holes that appeared along the seawall as I was living in the house over the years but it always seemed that it did not really fix the problem or if it did it was temporary.

There are many other ways to fix the leaky sand problem on seawalls.  However I had a land height problem as well.  I considered putting in a new vinyl seawall myself, but I had two issues.  I would have to remove and redo the dock and there was coquina rock next to the seawall making it hard to sink the vinyl sheets.  Because of this and the pricey cost of using a contractor to do it, I decided to build a 1.5' cement retaining wall behind the seawall with a deep footer all by myself.   I don't think anyone in the area has approached the problem this way.  So it ended up being new territory to explore and new methods to develop.  Little did I know I was in for some really shitty work.

To be continued in the next blog

Happy Building!

The Dr