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Floor on the right was 1" lower |
After taking down the load bearing wall between the old kitchen and the butler's pantry (read our previous post called "Kitchen Canvas"), we noticed how unleveled the floor was. In fact, it dropped by more than an inch on the breakfast nook side. It was simply too much of a drop to ignore it. So in order to fix it, we had to understand the root cause of the problem. Our investigation revealed a construction mistake dating from 1912. We could tell the architect probably designed it correctly, but it was the construction crew who most likely messed it up.
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Misaligned walls |
The load bearing wall that we took down was supporting the weight of the bathroom floor above, made up of 7 inches of concrete, and an iron tub. You should read VERY HEAVY!However, that wall was only support by the kitchen floor and not supported below despite a large 6X10 beam and a brick column in the basement. The error was a misalignment of the wall and the column. They were supposed to be directly on top of each other, however, the wall was offset by a foot to the right of the column. To make things worse, they notched the 2X10 joists so they could rest on a 2X4 board nailed into the beam (see the hand drawn sketch to the right). So the entire weight was resting on a single horizontal 2X4. Had the joists rested on the beam itself or had they been held by joist hangers, it probably would have resisted better. But without any support, that poor 2X4 didn't stand a chance. Therefore the joists sank with the 2X4 underneath.
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2X10 notched to rest on a 2X4 nailed to the beam |
The good news is that we took the kitchen wall down, therefore relieving all the pressure on these poor joists. This actually made the fix a lot easier than we had anticipated. All we had to do at this point was to lift each joist using a 20 lbs bottle jack and then shim below the notch of the 2X10 so it will rest higher on the 2X4 and voila! But just to be on the safe side, we also added metal joist hangers to support the joists.
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A shim inserted under the joist |
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20 ton bottle jack lifting a joist |
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Shim under the 2X10 |
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New sub-floor in select areas |
Once the floor was leveled correctly, we proceeded with repairs to the sub-floor. It had rotted from years of leaking pipes under the kitchen sink. The rotten wood spread for several feet. We used 3/4" tongue and groove decking instead of the diagonal pine boards used in the original construction, simply because we didn't have any extra pine boards. But since the sub-floor will be covered by hardwood floors anyway, nobody will ever see the difference, unless they are looking at the basement ceiling. Moreover, we salvaged as much of the hardwood floor as possible. We are keeping the pieces for repairs in other areas. For example, we will need to cover up old giant return vents that are no longer in use. Besides being the right restoration think to do, reusing original hardwood pieces has another important advantage. It just so happens that the width of these white oak boards are slightly thinner than the 2 1/4" boards sold today. So when you have to replace boards in between other boards, using new boards that are slightly wider won't work. Also the new wood doesn't take the stain the same way as old wood does. So this will ensure better consistency for the finished product.
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Chiseled joist forming a point |
Finally, with the concrete removed from the bathroom floor above, the last thing to do was to remove the chiseled joists on the second floor and put in new ones. Back then, they chiseled the top of the joists into a triangular point so they could level the concrete poured in between the joists (see picture to the left or read the previous blog labelled "Hammer Time" for more details on chiseled joists). Unfortunately, a chiseled point won't give us the nailing surface needed for the new subfloor. So we removed the old joists and installed new ones.
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Kevin removing old chiseled joists |
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Patrice nailing new joists |
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Upstairs bathroom floor redone |
We still have one more sunken floor that requires attention. It is on the ground floor in the central hallway close to the bathroom. There again we had 2 concrete floors and a load bearing wall that weren't supported at all underneath. We will need to dig in the crawl space until we hit solid ground. It shouldn't be difficult because the ground is quite solid in that area. Then we will pour two 12" deep concrete foundations about 8 feet apart. Once the concrete has cured for 48 hours, we will use these new foundations to install our bottle jacks and push a new 6X6 treated beam under the load bearing wall. We will attempt to level it as much as we can while being careful not to crack the plaster walls above too much. Once we reach an acceptable level for the floor, we will cut and install permanent columns under the new beam that will rest on the new concrete foundation. Then we will remove the jacks. Once this last floor leveling project is completed, we will be home free. That means we will be able to close up all remaining bathroom floors, run new pipes and wiring, retile all 3 floors, re-install tubs and sinks so we can have 4 working bathrooms again. It has been years since all 4 bathrooms haven't worked in this house. So I have a feeling the house will be very happy!!!