A Little Dreaming

Now that the block walls are pretty much finished, and stable enough to stand on top of, here is a view of what I will see out my living room when this house if finally complete. It has helped keep me motivated to continue working, when it seems that everything goes so slow.

Pic 2 and 3 are then and now pics. Though it may not look like it; the block wall (especially on the right side) is 8 feet tall.

An Update

The bond beam is pretty much complete now. Due to a different way of laying the bottom row of block in some of the north wall, the wall height came out a little shallow in several places. To compensate for that I just made the bond beam a little thicker in those areas. Net result, top of bond beam is at desired elevation (which means my floors will be level). To add that thickness I had to frame up the sides some (see pic 1). This method of framing worked well on the lintel beam, so I just used that method again.

On a different subject, I decided to make my first trial runs using the surface bonding cement. This is the mortar like stuff that contains fiberglass (for structural strength) and a waterproofing agent that is used to coat the inside and outside of dry-stack built block walls. I mixed up two small batches of SBC and troweled them on. See pic 2. It goes on pretty easily and trowels out smooth. I ran out of material so there is a small uncoated area in the middle. The instructions said to feather it out on top of your footers a little to seal the wall-footer contact area. My girlfriend said to go buy her a trowel because she wants to get in on this too. So, I’m off to the building supply store (again).

Tornado Shelter Roof

I expected pouring the 3” thick concrete roof for the tornado shelter to be a real challenge, but it turned out not to be nearly as bad as I had expected.

Pic 1 shows the shelter before the roof. Notice the top row of concrete blocks have been dished out to act as forms for holding the concrete.

Pic 2 shows the form boards in place. I used 4x8 OSB (3/4” thick) for the base. Pic 3 shows what held up the OSB base; concrete blocks stood on end. I built six pillars of block so that the floor would be supported roughly every two and a half feet in all directions. I did take care to make sure the pillars were vertical (used a level). On top of the pillars sets a 2x4 frame, with the OSB sitting on top of this frame. There were some small gaps around the OSB that concrete could go through so I used 3” wide strips of aluminum (.020” - twenty thousandths thickness) to close those gaps. They overlapped the concrete block by 1/8” to ¼” in most places and so they wouldn’t move were held in place by one dry wall screw on each piece.

I was afraid the weight of the concrete might push down too much in the middle, so I wedged 2x4’s there to help support the middle.

Rebar was then installed in both directions. Each rebar piece had 90 degree bends on the ends so the ends could stick down into the top of the concrete blocks to give the concrete more to hold on too and to better secure the roof to the walls. Unfortunately I don’t have a pic of the rebar installed.

Then came the concrete; I mixed it; girlfriend placed and smoothed it. One piece of rebar stuck up more than desired, so we just made the slab thicker there than other places. My plan was to have 1-1/2” between top of concrete roof and bottom of floor joists (the thickness of the sill), so the slab could be made up to 1-1/2” thicker locally and still not hit the joists.

Pic 4 is the completed roof slab. I left the forms up for three days and kept the roof as wet as much as possible while curing, but I didn’t cover it with plastic (should have). A week later now, no cracks.

When I took out the block pillars the OSB base didn’t want to come out easily, so I have decided to leave it in permanently. It will give us something to screw the lights too and after it’s painted we think it will look nicer than a concrete roof.

P.S. The holes in the walls in pics 1 and 4 are for vent fans and for emergency communication, should a tornado bring the house down on top of us (blocking our escape).

Lintel Beam

Here is the lintel beam that goes over the basement room door. It is actually part of the bond beam that sits on top of my foundation walls. It has four pieces of 3/8” rebar inside that run horizontally and two pieces that run vertically in either side of the door frame. Two of the horizontal pieces (the top two) continue on into the bond beam in both directions. The vertical rebar terminates in a 90 degree bends inside the lintel beam. Outside dimensions are the same as a concrete block (7-5/8 x 7-5/8).

It was pretty easy to build the form, using just three upright 2x4’s to hold it up and an OSB box built to shape and contain the sides.

The concrete used to cast the beam was a fairly dry mix and the aggregate was pea gravel, so it looks like an exposed aggregate surface finish. It will all be covered with surface bonding cement later, so the small voids won’t show.