I've been at this one for a long time, and now am coming to where it cannot be put off any longer: straightening the structure of my house.
This is one of those textbook definitions of the exclamation: oy.
In some quarters merely adding to a structure in parallel with the existing structure is considered repair and not needing a permit. In others, not so much. It depends. You need to have an inspection.
Well, my house is an embarrassment of wrong. Previous deviations from zoning code which were allowed to be and did not stop occupancy permits from being given to the previous owner (which grandfathers them to me as I took possession as a former renter still living there continuously) have to be fixed. The house's structure is laid out in what can only be called an unfortunate way. Long from east to west you'd think that they'd run the joists from north to south to a long series of main beams down the centerline. Nope. They ran two beams inboard of the foundation walls splitting the house into uneven thirds, the longest span being the middle between the beams.
Over the years since its late 19th century construction it has received several layers of wiring of various qualities and been reworked from original plaster lathe to new plaster lathe to oh let's say the fuck with it sheetrock over plaster lathe or even ugly paneling over plaster lathe.
Then there's the pet damage. Cats have whizzed in corners and while that can be cleaned to a point and what stains refuse lifting from the wood can be painted over, there's the issue of what they'll do to anything new. Dogs have also made a hash of the kitchen flooring by ripping up the seamless linoleum and whizzing on the wood. They're paper trained but I wish they could be toilet trained.
First I need to safeguard the future so I intend to get this thing from the manufacturer:
This is the Cat Genie self-flushing cat box. You heard right, a FLUSHING cat box. This would be ideal as I go through between eighty and one hundred twenty pounds of clumping cat litter every month and while the clay came from the ground and to the ground it returns with the trash, it still doesn't seem right. It also of course costs way too much. There's no reason to be doing it with this. As a fortunate bonus, my upstairs used to be a second apartment and since I've wrecked out the old kitchen I still have a septic pipe and water supplies. So, in my ongoing redesign I've decided I'll put a janitorial closet in at that point on both floors one over the other and that will take care of the problem of routing wires and pipes to the second floor very cleanly.
This also eliminates smells and you don't need to let them do their business wherever indiscriminately to get this smell, just wait one hour too long to scoop boxes and you will get it. It gets into your clothes and whatnot. No smells to build at all with this. No smells to build around the scooped litter pending trashing it either since there's no litter.
As soon as tax refunds get here, this is a must get, a will be gotten in fact.
Okay, with that taken care of there's still the dogs and what the cats might do to new floors. Aha! New floors! Yes, but what...
I have decided to push that back just a little behind getting the base for the floors right. There's uneven sagging midspan even long after loads that may have previously been there are gone. Not enough to disqualify it from occupancy and nowhere near enough to be dangerous but definitely annoying and I dislike them.
Sure there are self-leveling poured compounds, but they don't address why the span sags much less fix it.
So I have read up quite a bit on the fine art of fine tuning floors with hydraulic jacks and gotten it across to myself that 1/8th of an inch per day is the absolute maximum. You put screw jacks next to the hydraulic jacks and posts to hold the load once in place.
I also believe sistering to new joists can be effective in the way of stiffening them and will likely do that where necessary. However, that can only be a part of it.
In the same way composites engineering makes use of basic geometric principles used in construction to give better strength on the small scale such that overall a material is better, so too can we use composites engineering techniques to make a house better.
First, in a well done house of old the floors would have a first layer of flooring laid on a bias to the joists, that is, forty-five degrees to the joists. The finish layer would then go above it perpendicular to the joists and the nails passing through both layers to unite those layers, and nails going to the joists to hold them relative to the joists.
Well, those floor sections are strips of wood and can laterally slide against each other. Not much, but more than you really want. The nails also are a vastly more than imperfect solution to bonding. They can bend and shift a bit over time more than you want.
It would have been nice if back in the 1890s people had the construction adhesives of today but they didn't so bet your ass there aren't any beads thereof on your joists under that wood. The entire layer of the floor deck is more free than you think to move against the joists. Unfortunately for most of us, we can't just move elsewhere for a time and rebuild the house. We have to do it in situ.
Plywood is the most familiar composite material you know other than perhaps your own bones which grow in layers somewhat like trees grow in layers. Plywood doesn't slip against itself. Bonded under heat and pressure with layers of fibers laid in specific ways, it is engineered for high tensile strength, good resistance to breaking under various loads, and not to break the way a single piece of wood... would.
My house has one layer of slats. That's it. So I look at the slats, and I look at the plywood and I think of how the slats aren't bonded to the joists and how they aren't bonded to each other... Make them part of a larger composite structure...
Okay, first the beams need to be exposed hence plaster and/or sheetrock ceiling sections need to be removed. Then with the joists exposed they can be jacked into place... No, wait, we need the sistering members up. Okay, we tack nail the sistering joists next to the originals just to keep them up where we want them and then jack up the existing joists. Once in place over the span of a week or so which includes slow 1/16 to 1/8 per day increases and a day between for settling under active load (people living on it, temperature variations of the day, etc.) we then undo the tack nails and run construction adhesive along the side of each joist where the existing floorboards above meet it. This is not as good as one bead along the top of the joist under but with a bead on each side it is a miniscule fraction less.
Then the sister joists are glued along their faces to the beams they will help support, and nailed and/or screwed their entire length to the existing members. The nails/screws are to both provide bonding AND to act as a clamp to keep the wood together during the adhesive bonding and curing process. They use this kind of adhesive in new prefab houses that will stand up to hurricanes by the way.
Between the joists need go dividers. They keep the joists from twisting and deflecting to either side and are very necessary to the overall strength. Got wires and plumbing? The important parts are the tops and bottoms. Slip the top above the wiring and the bottom below and let the wiring pass between where it is.
With the next sistering joists in place, the temporary jacks... can not be removed yet. The floors aren't done. Why? Well, you've bonded whatever sections of whatever slats have crossed any given joist at those points which is a lot, but the joists and subfloor have too much ability to move. They aren't rigid and load-sharing yet.
The next step is a sanding of the existing floors. Cover paint, whatever, comes off. Now my floors have been somewhat finished and refinished over time but still some adhesion can be gotten. Some is better than none, so sanding needs be done to the newly leveled floor.
Once that is done, the floors need to be spread with construction adhesive. Surface spread, not beads. They have this stuff, you can look it up. Immediately over each 4x8 section goes the 1/2 inch plywood to which it will be bonded, and a small bead along the edge to butt to the next piece. Screws through to the slats, long nails through to the existing joists NOT the sistering joists and definitely not both. They will be too close together and the rule of not putting seams between two pieces of wood at the point of greatest stress applies.
Allow to set and cure.
After a week of time, the screw jacks can be knocked loose and removed. I'll now have a new floor and supports bonded to the original and only adding a marginal amount of weight to do it. A few hundred pounds spread and connected evenly across several hundred square feet in a way that my more than two hundred pound body isn't.
What has to be remembered is the the original beams sagged under load and stayed that way. They won't spring naturally into place and by now are so old and solidified they won't want to go straight which means in addition to any loads, the system has to resist the now natural desire of the wood to bend back to where it had sagged to. That's another reason for the glue, nail, screw method. Spread the stresses out. For one thing to move, it must move something else. A solid box structure is better than one that's...not.
Well, you can't really make a box short of putting plywood under the joists and while you could do that, make a floor section by section prefab with conduits and so on inside between the layers and insulation and so on... it's not feasible really in an already long ago built house.
The preceding description shows the next best option.
So what will keep the cats and dogs from destroying the new floor? 12 by 12 ceramic tiles which you can get on sale more or less all the time from various outlets, and you can get them over time and irregularly such that instead of a continuous design, you can vary the colors and designs on purpose for a much more personal and eclectic result.
Well, that's what's ahead of me to say nothing of the new (non-load-bearing) partition walls and painting and insulation and wiring... Should be fun and it will be blogged right here.
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