Sunday, February 4, 2018

11/2017 Cockeysville Retaining Wall, Happy Hollow

11/2017 Happy Hollow Road, Cockeysville Maryland. 28' l x from 2'-5' h retaining wall built with West Mountain Stone.  Flat caps built to the grade going up hill. Protruding foundation below grade. Tie stones set halfway up the wall set around every 3 ft.  mainly in the taller sections. The steps with walk I rebuilt with Colonial Blue Stone. This project had some very interesting turns along the way. 

The start was the timber retaining wall. I underestimated the amount of work it would take to disassemble this. I figure I'll come in with my mini excavated and thumb and just pick these 20 year old wood right apart.  I was so WRONG!

TIP 1. So if you need to know the tool of choice I would suggest a reciprocating saw along with a 9" carbide blade in order to cut either the nails, rebar or bolts which hold the timbers together. TIP 2 A few pry bars, crowbars and large hammer. Now the other thing I didn't pay much attention to since I don't build timber walls are all the corners they are extremely tight. They are the hardest things to dissemble when they lock to each other. Really no different than any other structure. The only issue with these were every other timber stat on time running the opposite directions. So you had to work your way down one at a time. 

One note regarding the steps with the wall. Typically I build my walls around my steps. In these situation I wanted to keep them separated. The main reason for this is so if either one ever needed to be repaired they could.  

The next thing I had to consider was the new wall would have below grade foundation and1:6 batter for the wall angle. Why I'm I bring this point up? Well notice the wall comes to the house corner there for I have a vertical section I need to build into. I kept some room in order for me to build a corner/column which was the simplest solution for the wall. 

Now the challenge with a corner is that you have to go long with every other stone. Plus stay on courses. While it solves the solution it does require a little more technical work.  I always love challenge. 

This was the start of the wall and steps removal. 

Timber by timber with a little help from the reciprocating saw.

One thing I didn't take into consideration since I didn't know. Was the driveway was installed after the wall was built. Now if you asking again why I'm bring up such a key point? When they paved the driveway they can only install so much blacktop. So the edges of the driveway was very thin like 2 inches. Normally I believe a good strong blacktop driveway should be about 4-5" thick. In the process of removing the timbers below the driveway areas of the black top caused some areas to lift. Take great consideration when stripping out existing structures. You just know what the other guy/gal did before you.

Now everything was removed and cleaned up. It was time to start working on the walkway. The wall build would be built after the steps /walk were set. The reason for this is the steps dictate the location of the wall along with the wall height. Most projects which would involve steps you start there first. Steps set the tone for the remainder of the construction. 

The one tool I love for digging out my foundations is the rapid hand digger. This is the tool sitting on the green turf. A few of the other issues I ran into was the space to place all the extra dirt which I had to removed. One thing which was changed in the design was the removal of the steps which had been built in the timber wall. Luckily this was a great place to store some of that extra dirt while I worked. You always should keep your materials close at hand. Extra steps create more work which is labor, and wear and tear on equipment. You have to think about every movement even the smallest steps add up over time.  Understanding staging is a key ingredient to one's success of job management. 

Related Blog: Tool - Rapid Digger

A few frames have been set as I start my build into the steps and then around the corner. Starting at the lowest point as I head toward the tallest section by the house. One other thing I use lot on driveways are rubber stall mats along with green turf. Both do a great job to protect surfaces. In addition make for easy clean ups.

One great thing in this image to show is the string line which sits on top of the last cap stones then goes to the house. This is the angle in which I'm building to as I stay on my courses. There are several different methods of setting caps or cope stones. I don't use this method much. I love this style of copes when they site on the top of a wall. 

This is the last section of timbers being removed. Making room for the last part of the wall. You might not have noticed but if you go back up in the images you will see many of the photos show the last section was kept in place. The reason for this is to minimize or reduce the failure of the bank falling down in the work area. Plus it just happens to be over 60" of retaining wall. A few other wonderful surprises I found when removing this last section by the corner of the house was the bug damage. Whatever was in the timbers eating decided to move to the house for dinner.  Moral of the story constructing with any material ie, natural stone, pavers, concrete, masonry.....other than wood for a retaining wall could save you alot in repair bills later. No one likes bugs eating there home. Do you?

I've included this example of a timber retaining wall that leaning forward.  This is too often the case with this style of construction. Unless it's new construction. This image even showing the rotten timber on the top.  This structure has the deadman but still is lean forward due to hydraulic pressure behind it. Deadman are what ties the timber walls back into the bank.  See the short squares in the wall? Those are the deadman. Timber walls may have a max life of 20 years typically more like 10-15 years is safe. Most railroad ties are in the same time frame. If you have a railroad tie wall you should remove it NOW! Why because railroad timbers have become increasingly hard to dispose of due to hazardous waste guidelines. Only a handful of place still will dispose of them at this time. I believe we may see the same situation with older treated timbers in the years to come. Just don't build with wood. It will be cheaper and quick and easy solution but your only asking for problems down the road. 

The other thing I encountered when disassembling the timbers from the house was the stucco on the house accidently came off when removing. The aged home of 20 years was week. The stucco process is over a styrofoam insulation. So one more thing to consider if your working with a home with this style of finish. It was a great accident since the homeowner need to patch other failed areas. Since he had a full blown wood working shop he also went ahead and fixed up all the damaged areas of wood at the corner of the home. 

On this jobsite image you can see a few pieces of equipment which help me out on the job. The one would be the Dewalt Hepa Vac for dust extraction. Time to time I'll use a diamond cup wheel on a grinder.  This helps when I have a few lumps and bumps - High spots which I can quickly remove. Minimizing wear and tear on my body and lungs. The dingo helps me with my digout along with moving the stone as I need more or less. 

In this photo one thing I didn't talk about was this retaining wall has double staggered tie stones. The tie stones are set about every 18" up the wall. So in the tallest section closest to the house I have my second group of ties. Tie stones which are also referred to as throw stones. Tie the two walls together. As the wall settles this acts as a floor to keep them supported above. The ties are protruding for a few reasons. The first is structural if the upper courses begin to settle the ties when sticking out act as a hand ready to catch them giving them that extra support. The second is to allow anyone who is a professional waller to quickly identify that this was built by a trainer waller. This wall will out last the life of this home.

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