Apr 192012

Concrete Away!

I’m adding on to my house to give myself a useable garage and some extra space.  Take the “I” literally; nearly all of this work I will be doing myself with help from my brother-in-law Mike!

If you want to read about this project from the start, go here.

The next thing to do is the footings. Footings are made of concrete and they provide a stable base to build upon. In my case, concrete “stem walls” (nearly five feet tall) will be placed on top of most of my footings and they need to have a stable platform to rest on.

There are several different ways to form footings.  You could actually just dig a trench to the exact depth and width but I thought that would be harder and required a digging blade of just the right width and some pretty precision work.  In our case, we “rough dug” the area where the footings will be placed and then formed the footings with lumber.

You can use “2 by” lumber such as a 2 x 10 to form the sides of the footing.  “1 by” would also work. Both of these options are fairly expensive. In the end, I decided to use 1/2″ OSB plywood for the task. Wet concrete is heavy so care must be taken to keep these boards from bowing out on the sides. A series of wooden stakes on the outside of the forms did the trick.

For footings, extreme precision on the width and depth are not required as long as the minimums are achieved.  In our case, the width was 18″ with a depth of 8″.

What does matter is making the top of the footings fairly level.  This will make forming the concrete wall on top of the footing easier.

The OSB was cut into 8″ strips and then laid out around the dimension of the project.  More digging by hand was required in some areas that were too high.  Other areas (most of the rest of it actually) was dug out too low.  Since the forms were cut to the depth of the footing, this meant that there were some gaps on the bottom.  To prevent concrete from seeping out from below the forms, dirt or rocks were thrown in.

Rebar Tie-In to House Foundation

The last step was the placement of “steel”; pieces of rebar which will give the footings additional strength.  These are by code to be placed 3″ from the side of the footings. Only two are required on footings less in 24″ wide.  The rebar is sitting on wire “chairs” to keep them elevated during the concrete pour.  Where the rebar met the footing of the existing house, 5/8″ holes were drilled and the rebar inserted. This helps to tie the two footings together.

Finally, we’re ready for the concrete!  I (under)-estimated about 4.5 yards of concrete for the project. It came in under mostly because of all of the extra volume cause by the over-digging.  Lucky, another yard or so was going unused on another project on the other side of town so it was sent our way.  We were *still* a bit shy so three bags of 80 lb. quick-crete had to be mixed by hand to level off the last few feet of the footing.

Handling the concrete chute was a learning curve and at first we had several “pour-overs”! But we just muscled the spilled concrete back into the forms.  As the pour continued, we got better at the hand signals to the driver while pushing and pulling the chute into position.


Rebar for the Tall Wall

After the concrete was poured, it was skimmed to the top of the footing forms.  Before it hardened too much, additional rebar was driven in vertically at three foot intervals.  This will make a connection between the footing and the concrete stem wall which will sit on top.

Next Blog: The Concrete Stem Walls

Mar 292012

Laser Leveling

The final things to do, before a storm chase and the rain, on my garage/house addition project was to carve out a rough idea of where the footings will be set and spread some stone around.

The old driveway/retaining wall made quite a pile but we had it removed. We still had the Skidsteer so it was time to carve out a level outline of where the concrete footings will eventually be placed.

Level in this case is fairly approximate but still required the use of a laser level. The one we rented from General Rental was self-leveling once the tripod was fairly level.

The principle here is to send out a level red laser beam reference. After that, our measuring stick and attachment could be used to sense the beam from anywhere in the project area.

We found the bottom of the existing house footing and used it as a guide. By taking a reference measurement “below laser” at this point, the stick could then be carried around the site to check the depth of the footing dig out.

Stakes where placed in the ground marking the center of where the footing was to be placed. The stakes were outside of the dig area and served as a line of sight. These stakes didn’t have to be perfect, since the scoop on the Skidsteer was much wider than the footer. Dirt was scraped away over a few passes, each time, a laser measurement was taken to see if the proper depth had been reached.

Bottom of House Footing

Concrete footings are very important as they serve to spread the load of the concrete retaining wall that will be placed on top of them. Our footing will eventually be 12″ across and 8″ deep.

When placing a footing two things are vital. First, it must rest on compacted soil. This is to prevent undue settling. Second, it must be below the frost line. For this area, this depth is 18″.

Finally, the load of 3/4″ stone I had dumped nearby was distributed best we could in the entire expansion/garage area since it will all be a concrete slab eventually.

Next Blog: Building and Prepping for Concrete Footings





Mar 232012

Chunky Driveway!

Last week while on vacation and before the rains came, I started on my new garage and house addition.  In my last blog, I explained why I’m doing this and a bit about the planning.  Now, let’s rent some machines and tear it up!

My helper on this project is my brother-in-law Michael Vengalli.  He’ll be with me through the entire process!

The first step involved cutting out the concrete curb which defined the old driveway.  The new driveway will be shifted down about 12 feet from where it is now to allow for a smoother approach to the new garage.  We rented a hand-held concrete saw from The Home Depot to make the necessary cuts.

Now for the fun part!  Wildcat Rental delivered a Skidsteer to us with a jackhammer attachment.  The idea was to use the jackhammer (which can be set horizontally too) to break up the old retaining wall and then to punch holes in the old concrete driveway.  Then the bucket attachment would be used to pile the concrete pieces up in one place to be hauled away.  Thanks Scott!

Cutting the Curb

One reason this idea worked is because no “steel” was used in the old driveway.  This means no enforcing pieces of metal were put in place to hold the concrete together.  This can either be a mesh or rods of “rebar”.  If they had been used, it would have meant the pieces of concrete would have been tied together and difficult to separate.  FYI, steel WILL be used when the new driveway is poured!

The retaining wall came down easy.  Bad design. It wasn’t sitting on a footing, it had hollow sections with loose bricks in the center and had absolutely no provision for drainage. It’s no wonder it was cracked and falling over!

Punching holes in the driveway came next.  This was time consuming but it worked fairly well.  Once finished, the pieces of old driveway were easy to remove.  The pile got pretty big!  Lafollette Excavating out of Strafford came to the rescue with a big loader and dump truck to haul it all away.  They also dropped me a load of “3/4 stone”, common fill for garages and slabs of concrete.

Next Blog:  Preparing for footings





Mar 212012

Garage Addition

Well my last two vacations were relaxing and/or fun (Mexico/Walt Disney World) so I figured I’d do some work on this one. That is before the rain and storms!

I acquired a house which has an unusable garage. First off, the garage is too narrow, only 18 feet wide. It’s also built so close to a retaining wall that it makes using it pretty much out of the question, unless I buy a clown car!

So, I’m basically going to add an attached garage to the house and in the process expand and free up the old garage for play area for the kids.

The first step in a project like this is planning.  But before I could even do that, I needed some details about where exactly my property lines were and where any easements and utility lines may be located.

My first call was to Global Precision Survey.  They located my property pins so that I knew where I can build and where I can’t  Just so you all know, in most cases, your property line is NOT the street.  In fact, my property line is about 10 feet off the street in question.

Old Garage and Retaining Wall

Then, there are setbacks.  For a side project like mine, the setback is 15 feet. Therefore, anything I want to build on this particular side of the house was going to have to be 25 feet off the road. This then gave me some idea on how to proceed.

Next, I loaded up my house design program, Chief Architect, to start planning how I was going to do this.  I wanted my garage to be attached to the old house in some way insead of free-standing.  Because of the 25 foot resctriction, I had to shift my garage down to the corner of my existing house.  Also, because a retaining wall is involved, I was going to need a concrete stem wall to hold the new area of fill.

The enclosed plan shows in detail how it’s all going to work.

Plan for Garage Expansion

My brother-in-law and I plan on doing much of the work.  I’ll have additional blogs and videos to present as the work progresses!

Next blog:  Tearin’ it up!