Mantle

One of the things that we wanted in a house was a wood stove for an alternate source of heat. The typical problems with this are that the stove is only hot when it's on, and when it is on, you can have too much heat. I have many ideas for active methods of heat distribution (circulating hot water or air) but more on that later. I want passive thermal storage. A massive stone mantle and hearth would be beautiful and functional. Natural stone from the property would fit the motif perfectly. We picked the corner of the family room centrally located--right next to the new foyer bathroom and in the old entry way.

Since the concept called for a thermal mass that was...massive, there was no way that the existing structure would be able to support it. This meant digging a new footing and foundation wall to support it. The architect’s design called for a 4 by 8 foot footing, 1 foot thick, and a 3 by 7 foot foundation wall on top, 3 foot high. The rest of the mantle will come later. This work had to be done before the new foyer bathroom because an existing floor beam had to be removed and replaced with the new foundation wall.

Preparation:

The first thing to be demolished was the foyer closet. I cut it up and established a debris pile in the back yard to put anything that I couldn’t disguise as household rubbish. Then, I had to move the front door over. The framing was already the right size so it didn't take too long. Next, I erected a plastic tent to enclose the whole area of work. I had hoped that this would contain most of the dust-didn't. Then I removed the floor in the area of the new bathroom and future hearth, an area about 8 feet wide by 16 feet long extending from the front wall of the house through the foyer and into the family room. This was tough work, sawing through nails and prying up the plywood.

Digging the Mantel Footing

I drove to Hoboken and picked up Pete at 7:45 AM. We went to pick up the laborers that I had prearranged. They were a little late because of the train. We were back at the house by 9:00 AM.

As they started digging I went out to the rental place to rent an electric jackhammer to take down the indoor terrarium block liner which is going to be the new entrance foyer. The joists have to be extended and new flooring has to be put down. This work was just getting the old stuff out of the way. The digging was very hard. The ground was very rocky which meant a lot of pick work and loading the rocks in the buckets by hand. After that, the dirt was loaded onto 5 gallon spackel buckets and taken to a wheelbarrow outside. When it was full, it was emptied in the back to help fill in an access road to the back of the property. Elaine picked up some pizza and we broke for lunch around noon. The footing was mostly complete. There was another smaller shallow footing that was also being dug to support the knee wall under the dropped joists for the hearth. The demo work in the new foyer was also complete. We were done and in the car by 2:00

Footing:

On Sunday, a mason came by to take a look at doing the pour. He said that it was a quick job. The only question was whether to get the cement delivered by truck or to pick it up himself. Picking it up would be cheaper, but he could only carry 1 yard and we needed 1.5 yards or so, which meant two trips. The other issue was to build ramps for the wheelbarrow or to carry it in using buckets. He figures about 10 wheelbarrows per yard, and many more buckets. Buckets would take longer but the ramps would probably be too steep for a wheelbarrow. Either way he was glad to help for about $200 labor. The cement was $100 per yard. He also told me that the inspector would want to see the re-bar set up- wired together and stood up on bricks. After he left, I went to Home Depot (who else would be open on Sunday afternoon) and bought the #4 re-bar and galvanized wire. I used my saws-all to cut the pieces to length. The re-bar is very hard, I dulled a few blades, but got it done.

I picked up the construction permit the following Monday, 23rd. I asked for a footing inspection and set it up for Tuesday. Inspectors will never give anybody an exact time, so its Tuesday morning and I am waiting for him to show up. He didn’t make it until the next morning.

I scheduled the mason for Saturday morning. He arrived at 9:30 with the cement and three workers. The buckets were loaded in the driveway and carried inside and dumped. The second load of cement finished everything up. The mantle footing ended up to be 1 1/2 foot thick, and the hearth knee wall footing, and the new entrance foyer crawl space slab were complete as well. The mason was finished by 11:00.

Building the Mantel Foundation Wall

On Monday, I figured out that I had a major job to stage laying the block wall by the following Saturday. I sketched up a block plan and calculated that 60- 12"x8"x16" cement blocks were needed. On the way to work I stopped at Clayton Block on route 1 in Edition. I bought 12 blocks and a 92 pound bag of portland. At this rate I wasn’t going to have enough time to get all the supplies before Saturday. Night runs to Home Depot would have to supplement daily block pickups. How much sand would I need ? The cement block cores had to be filled with 0.4 cubic feet of cement each. (I measured) That added up to 1 yard (cubic yard) of cement just inside the cores! If you figure 5 bags of portland in 1 yard (500 lbs) and 3 times as much sand (1500 lbs), that’s lots of back intensive labor. I got the sand at the Depot in 2 trips with the pickup. One more trip for block with the pickup, and 4 trips to Clayton Block in the Pathfinder for block and portland. To get the block from the driveway and piled up by the footing, it was a 3 stage process. The first step was from the driveway to the upper stair landing. Then from the landing to the edge of the pit, and finally to the crawl space under the living room. The cement and sand was stacked by the front door- all completed by Friday night.

In the end, I wound up carrying in 10 bags of portland (1,000 lbs), 54 bags of sand (2,700 lbs), 6 bags of gravel (300 lbs), and 60 blocks (1,800 lbs)for a total of 5,800 lbs.

Laying the Bock

I woke up early and prepared for the day. I still had 21 bags of sand in the pickup that needed to be moved up. I had quit early the night before because my back needed a rest. I was imagining the mason showing up in the morning and me being unable to get out of bed from a strained back. During the night my back recovered so the 21 bag move went OK. When I was getting the tools out the mason showed up. We moved the cement mixer that I had borrowed from a friend up to the front landing and mixed the first batch. We then went to lay out the wall. The dimensions called for were 7’-6" by 2’ at the base. The problem was that an existing pier was in the way. The corner block had to be left out. This created an ‘L’ shaped void down to the footing.

The mason (John) laid the block and I made the cement. My good friend Peter showed up to help. We ran out of cement by 1:00 pm and couldn’t lay the last 2 blocks because of the pier void.

On Sunday I made a steel frame for cement reinforcement and enclosed the void to make a cement form. I made sure that the form went all the way down to the footing. It wound up taking 2 bags of portland, 3 bags of gravel, and 9 bags of sand to fill. I laid the last top block the following day completing the wall.

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The new masonry for the mantle ended at the family room floor level. This wall had to be extended up to the ceiling to protect the wall from the heat of the wood stove and flue pipe. Our plan was to put up a cement block wall, and use it as a backing for a natural stone facing. The archiect called for 8" block, filled with cement and #4 (1/2") re-bar. I decided to use 6" block from the floor up to 5’ and 4" block above that to the ceiling. I called him to check and see if it was ok, but he is not returning calls these days. I went ahead with it anyway. I thought that using different thicknesses of block, and a mantle would visually separate the upper and lower parts.

I had Home Depot deliver 50- 6" blocks, 60- 4" blocks, 20 pieces of 4’ re-bar, and 10- 92 pound bags of portland. It almost worked, they forgot the portland and had to deliver it the next day. At least they were able to but the pallot of block right by the back porch door. On Friday I moved the block into the house and piled it in front of the hearth in the family room. I had my trucker friend Dominic Celebre deliverd 5 tons of sand and dumped it at the end of the driveway.

I scheduled the mason, John, and my helper, Weed (Pete Rebovich) for 7:30 AM on Saturday 3/27. Elaine was off on another business trip this weekend.The mason showed up on time. Laying the block went pretty quick. Brick ties were screwed into the wall behind the block and laid into the mortar joints. In the front, the ties ware laid into the mortar so that half was stickng out to help attach the future stone face. Cement was brought in with a wheelbarrow. I used my truck ramps to get up the porch stairs. Around noon he had to go pick up his scaffold to reach the upper part of the 11 foot wall. He was done by 3:30 PM. We made about a little less than 1 yard of cement which took about 4 bags of portland.

The next day we prepped and poured the hearth slab. Weed helped again. The slab form was made with ½" plywood on the joists, and ¼" around the perimeter. In the slab was ½" PEX tubing for the radiant heating, sanwiched between 2 layers of 6" steel mesh. Paul Gee came by to help with the pour. The night before I had to make a trip to the Depot to pick up 600 pounds of gravel. The mix proportions were 1:3:3 portland to sand to gravel. The slab took about almost ½ yard. It took about 6 hours to set up before I could re-float it.