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67

Absolutely not safe. Those trusses were engineered with a heavy (critical) dependency on the bottom chords, which are in tension. Removal has left them extremely vulnerable to collapse due to spreading, especially under snow loads, but also under just the load of the roof itself. The roof system is basically a hinge now. To get a good mental image, ...


35

Have a look at this document for a quick reference. This type of thing will be covered by International Building Code (IBC) and International Residential Code (IRC) IBC 2308.8.2 Framing details. Joists shall be supported laterally at the ends and at each support by solid blocking except where the ends of the joists are nailed to a header, band ...


31

With no bracing above, you might want to check the out side walls - they are probably already spreading. Once they start moving the stabilization and repair can cost many thousands if the roof stays in place, tens of thousands if it comes down. There are ways to mitigate the damage done, but it needs to be done now before the walls spread, the rafters ...


25

No, it’s not acceptable to cut the joist hangers. In order to determine if they are acceptable anyway, there are several issues to review: 1) hangers are notched, 2) incomplete nailing, 3) wrong nails, 4) wrong install of fasteners (angled install in lieu of perpendicular to joist installation). 1) Notching the hangers voids the allowable stresses ...


20

Don't do it. The reason that you can drill through the face of a beam in the center is because the bending stress is essentially zero there. If you drill from the top to the bottom, you're removing the portions that carry the brunt of the loading (the top and bottom of the beam). If a joist that big is sistered, there's a good bet that it's a major load ...


18

The triangle is an extremely stable form of architecture precisely because it has three sides. You remove one side, and you have one of the least stable forms of architecture on account that two members connected at a point can be affected by torque, which is by definition a force multiplier. If you want to play around with it to get a sense, try gluing two ...


16

According to this document (PDF), accidental notches in the top flange may not need to be repaired if they meet specific criteria. To determine if a repair is required, we'd need a bit more information, including: The distance from the center of the notch to the end of the beam. The depth of the notch. The specific beam used, including beam height. If a ...


14

Only if you're a "professional" plumber. Cut twice as much & then measure, hey lookie there just like they did in your place. Seriously no, you're completely right the I's of I-joists are NEVER to be touched nor any holes within 3" of the top or bottom edges. "Responsible" plumbers & builders re-spec a toilet with a deeper stand-off or just pull it ...


14

Point your home builder to page 9 of Weyerhauser's I-joist document here. See the bottom right of the page where it says "DO NOT cut or notch flange" It is typical of all I-joist manufacturers' installation documents. As Iggy pointed out, the I-Joist in question needs to be reinforced similar to a cantilever reinforcement. To fix this, the electrical ...


13

The reason that joists are sistered using the same height of wood is simply space; generally there's no extra room. If you've got nothing below and there's space then there's no reason you can't use a taller piece of wood. Things to keep in mind: Spanning as much distance as you can so you transfer the load as evenly across the original joist. If it's too ...


13

Good question Paul, The situation with your framing is not really normal, but not uncommon for a house that age. Any time there is separation of framing members, it is a reason for concern and should be addressed. However, I would not say it is a major or alarming problem. There could be a couple of different reasons for this separation. The joists may have ...


12

As pictured - very bad idea. It may work IF the roof is re-engineered to carry a lot more of the stress across the top and bottom of the cutout. That means a much beefier horizontal beam on all four sides of his hole AND a rework of the roof by re-trussing the entire structure. Some examples: This one is a Scissor Truss, and also wears the more ...


12

Cutting a hanger is never a good idea and should never be accepted. It's shoddy workmanship by the contractor and there were numerous solutions that could have avoided this (starting with properly measuring the bolt locations for the web blocking). However, the main issue is that these hangers are not designed for this application. They are meant to hang ...


10

Another method is to get pliers and a block of wood about the height of the extended nail ( protruding out the wood). Grab the nail out the side of the pliers and insert the block of wood between the joist and the head of the pliers. then use the leverage to pull the nail out, this is also great because it will not damage your wood.


9

If you're covering them over, then a wack with a hammer so they go all the way into the joists should be fine. That's routine during a demolition. If you absolutely need to remove the nail, then get a large channel lock plier, grip the nail tight, and roll the pliers on their head to pull the nail. The long handle gives you lots of leverage to hold the nail ...


9

We usually use one of these standard nail pullers. Grab the nail shank and roll the plier to pull the nail out of the board. It has the best leverage out of all the recommendations here. Available from several manufacturers, end nippers such as Diamond horse shoeing nippers have longer handles for better leverage and the wide head doesn't dent the wood as ...


9

You never cut hangers unless they are made for cutting. Call in a inspector who will advise you or the engineer who done the design but don't under any circumstances let this go without it being checked. As further down the line could cost you a lot of money.


8

I just checked some Ontario tables. For an Attic, not accessible by stairs (i.e. not used as living space, a 2x12 every 12" can span 32 ft. But you can't put anything above it. I've found nothing in the tables that allows a 30 ft span supporting a floor. While this doesn't mean it can't be done, it means you need to consult with an engineer, and pay ...


8

Nah - most of the strength is in shear, and joist hanger nails are nice and fat so they have good shear strength. also, yanking them is likely to be harder than you think. The actual nailing schedule seems to be here: http://www.strongtie.com/products/connectors/H.asp That suggests that 10d are one size larger than you should use in a model H1Z hanger (...


8

You don't have joists or rafters. You have engineered roof trusses. The bottom chords are 2x4 because that's all that's required for your scenario. They don't span the ceiling themselves. They're part of a rigid structure that's supported by both the top chords and the diagonal truss members. This is typical and has been standard practice since the 1970s ...


7

Are the tongues necessary? Can I just take my circular saw right between the boards, cut them way, and then screw them back down afterward? You've been misinformed. The point of tongue-in-groove planking is to keep the floor boards from twisting, slipping and sliding against each other and squeaking (or squeaking more in your case). You still need to ...


7

First off let me quote the American Wood Council PRESCRIPTIVE RESIDENTIAL WOOD DECK CONSTRUCTION GUIDE (which I recommend looking through). MANUFACTURED WOOD I-JOIST: Many new homes constructed with wood I-joists include 1" or thicker engineered wood products (EWP) – such as oriented strand board (OSB) or structural composite lumber (SCL) including ...


7

OK normally load bearing walls will have 2 plates on top. But having 2 plates means nothing. People frame however they learned to or want. Checking door header also means nothing. Some people flip all door headers - doesn't make the wall load bearing. You can never get into the head of the guy who framed your house. I worked for a construction ...


7

Yes, this is common. The load in any joist is carried in the top and bottom surfaces (the flanges) of the joist. That's why I beams/I joists work. The thinner web between the flanges basically serves to keep the flanges at the same distance from each other. There is no load in the center of the web. Thus, the center of the beam does not need to be the same ...


6

Since you can get to the floor from underneath, you can shore up the flooring by adding new joists between the existing ones. This will not be a FUN process, but the process is simple enough, just labor intensive. First, add cross braces between each joist at each end, of the same dimensions as your existing joists. You'll want them to be snug fitting ...


6

No. Since the band (rim) joist is continuously supported by the foundation wall, the boring and notching rules do not apply. You will, however, want to use common sense. Try not to notch or bore directly under a window or door, especially right where the king/jack studs are. You also don't want to notch or bore the entire width of the joist, in other words ...


6

Replacing them? Getting an engineer? For a 1/2 hole in at least 8in joist? Seriously? I mean I'm sure the joist has lost some percentage of its strength. Like pretty small percentage. I would speculate that the lost strength is within tolerance limits for wood, which is not uniformly perfect. Unless you plan on having sumo wrestlers fight on top of those ...


6

Weight isn't going to be your issue here. 2 inch furring strips may be pretty hard to hit with the drywall screws. The screws need to be in good solid wood and not going through an edge etc. If You are careful, caulk some good lines, the 1X2's might work for ya. The other consideration is if the spacing is good and you have enough surface to butt pieces of ...


6

I'm confused/surprised by the existence of the void, but if you've got the space, then go for it. The only bit of mathematics to be concerned with is matching the cross section of the various sections of pipe.


5

It is always best to consult the manufacturer's manuals and catalogs on this. Simpson Strong-Tie is one brand that is very extensively documented. If you're talking about the diamond plate type, they belong on the outside of the building, and tie the double top plate strongly to the rafter. If you use them on the inside, they only catch the lower truss joist ...


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