Questions tagged [engineering]

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7
votes
5answers
3k views

Repairing a notched floor joist

Situation I was running some new gas pipe and I notched one floor joist and drilled a hole in another. I have now learned that this is not appropriate. This was in the forbidden zone of the middle 1/...
0
votes
0answers
46 views

Frame a jack stud without bottom plate?

I need to frame a small header in my kitchen exterior wall for a range hood exhaust because the 8" hole is dead center on a stud (of course). It's a 2 story 1941 house with 2x4s 16 on center. The ...
0
votes
1answer
56 views

Simpson A-35 (framing angle) suitable for this application?

Would an A-35 be suitable for the rafter>top-plate connection shown here? Would I need one on both sides of a rafter, or just on one side? Existing structure (grey) is 12'x 18', 6" CMU block w/rebar, ...
0
votes
1answer
83 views

Steel beams for 22' interior clear span

I am building a ceiling under an existing roof, covering an area of 22' x 28'. This rectangle will be supported at the two ends of the 22' run, as well as, optionally, one or possibly two ends of the ...
0
votes
0answers
44 views

How to frame corner of staircase header for a stairwell opening? Do you use a hanger here?

I'm designing a staircase and was a little curious on how to frame out the stairwell opening where the header meats the existing joists. There will be a double 1.75"(x2) LVL header joined up against ...
12
votes
7answers
63k views

What is the optimal configuration of a cross brace on a wooden gate?

I'm building a wooden gate for my deck, and I want to put in a cross brace to reduce sagging. I want to install the brace so that it transfers the load from the top unhinged corner, to the bottom ...
0
votes
0answers
27 views

Which Installation position of expansion tank is more technical [duplicate]

If there is two expansion tank of the same volume(same diameter and height) ,which position of vertical or horizontal direction is technically better to be installed.
0
votes
1answer
176 views

How much weight/many people can my rooftop deck hold? 2“x12”x20' joists, 16“ on center, 2”x4" framing under [closed]

How much weight/ How many people can my rooftop deck hold? The joists are 2"x12" over 20ft, 16" on center The framing under the deck is typical 2"x4" framing (living space), on a concrete ...
1
vote
1answer
123 views

Could I move a piano ALONE this way?

To move a piano from a first floor to another first floor, using a pickup truck, it seems like a ramp, a strong rope and some pulleys, and a furniture dolly would suffice. Plus a basketball and pump (...
1
vote
0answers
65 views

Fujitsu Halcyon: Custom Air-Filter (C.F.M.)

I'm trying to make airfilters to fit over my Fujitsu Halcyon Wall Mounted heating & air-conditioning split system. I'm talking about the indoor unit specifically. The wire mesh screens that come ...
1
vote
2answers
515 views

A-frame swing set max length of 4x4 beams

I am building an a-frame swing set for my kids using a 4x6 and 4x4 beams. We are using pre-built brackets to attach everything. What I am wondering is, is there a max length that the 4x4 can safely ...
32
votes
10answers
8k views

How do I stop a creek from eroding my steep embankment?

Behind my house there is a very steep bank/slope that leads down to a decent-sized, slow moving creek about 10 - 12 ft wide. Unfortunately it meanders right behind my property at the base of this ...
0
votes
0answers
57 views

DIY Pool Lift designs & successes?

My dad suddenly has serious mobility issues keeping him from his beloved pool. I’m visiting this week and trying to see if there’s some diy pool lift of any design I can build from stuff at Harbor ...
0
votes
1answer
368 views

Load-Bearing Wall? Parallel to Joists, single story, but has attic supports [closed]

I've had multiple professionals look at this wall, and no one has been able to give me a clear answer (2 home inspectors, and 1 structural engineer). So I've come to the source of all truth, the ...
1
vote
2answers
626 views

Fix wobbly storage shelf

I just built this storage rack for my basement out of 2x4s and plywood. It is relatively stable but does have some front to back wobble. More than I would like. Is there a way to increase the ...
4
votes
15answers
19k views

What is the cheapest way to stiffen a tube/pipe?

I have some steel tubes (18 mm OD) which I wish to use as horizontal members in a storage rack (a bit like shelves). However, the tube flex and bend quite a bit when I put heavier boxes on them. The ...
3
votes
4answers
14k views

How to calculate steel beam and posts size to replace existing wood beam in terrace

I have a covered terrace that extends 10' out (West) from the house towards the yard/pool and has a width/span of 32'. The current beam is made up of (2) 2x6 in wood placed side-by-side functioning ...
0
votes
1answer
43 views

Are there any join charts similar to span charts?

Are there any charts indicating what type of joints are stronger than others? For example, how would one determine which of the following joints is stronger? Intuitively I'd say longer cuts ...
0
votes
0answers
275 views

How to cantilever a roof beyond the end wall?

How can this roof be extended 16 inches beyond the end wall? Seems like it requires some 8 foot 2x4's but I'm unsure how to brace them to the truss. My way of thinking would put them above 4 inner ...
0
votes
1answer
19 views

Is there any advantage to using larger stones in a free-standing dry stack wall?

I'm building a free-standing dry stack wall using ashlar scrap from a quarry (pieces of uniform thickness with completely flat top and bottom faces, but irregular sides): Within each course of the ...
0
votes
2answers
366 views

Is a 15 foot tall pergola not feasible?

Looking for some structural wisdom :) I have a deck that sits 6 feet off the ground, and I want to build a pergola whose "roof" (beams/slats) are 9 feet above the deck. So, from ground (grass) to ...
0
votes
1answer
42 views

Goal: make hardwood slats for a bed thin to flex, w/o degradation

My goal is to make hardwood slats for a 4' wide bed, (center support, so span is 24"), thin enough so my heavier parts flex, adding comfort so I can minimize mattress. (Ideally, pad will be 1 inch ...
0
votes
2answers
2k views

Cantilevered roof overhangs

Are there good options for attaching roof eaves/overhangs essentially as cantilevered beams with a fixed support? This is a monoslope (lean-to) roof with a 2:12 pitch (~9.46 deg), unheated structure, ...
0
votes
0answers
400 views

Mid span weight capacity

What is the mid-span (center of wood board) load bearing capacity of one 2”x12”x10’ setting on edge. I will be mounting a 1 ton chain hoist by a 2”x36” tow hook strap rated up to 3,300 lbs dead load ...
1
vote
1answer
284 views

Removing or replacing a post supporting a bolted joint in a long glue lam beam [closed]

We bought a home to remodel - and taking down a wall we found that our gluelam beam is actually two different beams, held together with some steel and bolts, and supported by a 4x6 vertical timber. We ...
1
vote
1answer
329 views

Calculating time constant for storage-tank water heater

I was curious what the R-C time constant is, for a conventional storage-tank style electric water heater; I came up with an answer that seems very counter-intuitive. ("RC time constant" is the ...
0
votes
1answer
92 views

dig out and finish my crawl space into a basement

I have a house with a continuous concrete stem wall, and a sill plate seismically bolted to the foundation. It's on a hillside, and the north (downslope) is post and pier (not continuous). There are ...
2
votes
2answers
642 views

Overkill from my Structural Engineer, can you check his drawings?

I have a cape I am moving the stairs and dormering the back. My engineer sent me these drawings. I think its overkill that he put HSS steel posts with w6x25(steel beam) across for the support. He has ...
1
vote
1answer
51 views

How do I determine what load values I need to use when using door/windows header sizing tables?

I'm designing the framing drawings for a building with window and door openings in a roof-bearing wall (no floors above) and I need to determine how thick my headers need to be. There are span tables ...
1
vote
4answers
9k views

Does shear strength increase with the number of fasteners?

Let's say I have screws with 1,000 lbs shear strength. If I add more screws, does the total shear strength of the joint increase? If I use 3 screws, then put a 2,000 lbs shear load on the joint, ...
1
vote
2answers
2k views

How are grade-level garage slabs typically connected to a basement wall?

When you have a basement wall that needs to join up to a garage slab at the top of the basement wall, how are the footings for the garage slab placed, and how does the garage slab attach to the ...
1
vote
2answers
109 views

What kind of connector is this and where do I find it?

I recently bought some electric solenoid valves online, and I don't know what kind of electrical connector this is using, and where to get a female version. Does anyone know where I can find the ...
2
votes
2answers
807 views

Does beam orientation matter for structural engineering calculation values from wood supplier tables?

One can get values for load bearing of simple wood constructions and thus the right beam profile dimensions to choose from tables from wood supplies (e.g. http://www.merkleholz.de/en/Static-table-KVH-...
27
votes
9answers
280k views

How much load can a (wood) board support, if it is supported only at the ends?

How much load can a board support, if it is supported only at the ends? At the moment my specific problem is hanging a tire swing between two trees, and depending on which trees I choose they could ...
1
vote
1answer
300 views

How deep should piers be for a concrete block fence wall?

I am wanting to put up a 1.8m high (besser/cinder) block wall that spans 10 meters across our rear boundary. The wall will be tied to both other neighbours walls also. The council water main runs 1.3 ...
0
votes
0answers
75 views

How do I make my floating shelf stronger/less susceptible to vibrations?

I'm building an entertainment center. I plan to put a turntable on the middle shelf in the picture below. There will be a floor standing speaker directly below the shelf. I expect the bass from the ...
1
vote
1answer
131 views

Correct placement for 1,200 lb pizza oven on wooden box I built

I am not much of a DIY-er, but I decided I wanted to try and make a stand for a 1,200 lb pizza oven I wanted to buy. I built a box out of 4x4's, and wrapped it in 5/8" OSB. The dimensions of the ...
0
votes
0answers
487 views

Permanent greenhouse structure materials

I'm planning a permanent greenhouse structure that will be attached on one wall to my house. The estimated size will be about 16ft wide, 45ft long, with the lowest wall being approximately 9ft tall ...
1
vote
1answer
5k views

Replace load bearing studs with 4x4 posts

I would like to open up our dining room to our living room, but don't want to install an LVL due to a limited budget. We decided to get creative. By simply removing the sheetrock, and using the ...
1
vote
1answer
1k views

Glass thickness for plywood tank

Apologies if this question is misplaced. I'm needing to know the required thickness of a glass viewing window when installed in a large plywood/steel constructed aquaculture tank (for a home / DIY ...
1
vote
0answers
108 views

North Carolina Code question for splicing 6x6 posts

I have a 48 X 10 second floor deck with 6X6 posts. I want to add a roof above about half of it. It is not feasible to replace the 6X6's with longer ones as I would basically end up replacing the ...
1
vote
2answers
935 views

Unsure about my structural engineer, can you check his drawing?

I recently asked my structural engineer to provide some calculations and drawings to remove the arch and further open up the opening between the double fronted sitting room of my 2.5 storey (2 at the ...
1
vote
1answer
711 views

Furniture calculations

I make camp furniture. I have been using pine for quite some time, but would like to shift to hardwoods. My questions is thus: How do I determine the equivalent strengths between 2 boards? For ...
77
votes
12answers
51k views

Is there a case where nails are better than screws, from an engineering/structural standpoint?

Is there a case where nails are better than screws, from a structural standpoint? For instance: Say you used screws instead of nails on a backyard deck, when the design specifically called for nails. ...
1
vote
1answer
162 views

How should I go about removing these two walls?

We just bought our first house, so go easy on me as I’m not an experienced DIY’er. I have read the documentation available on planningportal.gov.uk, but am still very confused. We’re hoping to remove ...
1
vote
3answers
2k views

Fix sagging beam situation

We've got a beam that we replaced two years ago due to some damage. The beam is out front and is above all the other beams it supports, which makes the whole thing a bit strange. We made our own ...
1
vote
0answers
53 views

Calculating Tie Plate loading and double shear

I am considering the use of L strap ties from Strong Tie. I will be connecting two 4x4's in an L-configuration. The image at the very bottom-right corner of the below PDF illustrates exactly the ...
4
votes
4answers
9k views

How can I hang a 250 lb wooden piece of art on the wall?

I have 3x8 Brazilian Cherry timbers cut with tongue and groove that stack on top of each other to make a very large wooden piece of art to hang on my wall. I have all of the pieces glued to each other ...
2
votes
2answers
5k views

How can I calculate the rotational force and motor HP needed to lift a 5lb sheet from a horizontal position to a vertical position from one end?

Essentially, I need to know the following: How do I calculate the rotation force along a fulcrum? Is there an equation? What is the weight of a 5 lb object at the fulcrum if the fulcrum is located at ...
1
vote
3answers
60k views

My 5th (top) floor apartment is shaking; what might cause this?

I live in a developing country (so don't have much faith in building codes), and have been experiencing increasingly noticeable and frequent "shaking" in my top fifth floor apartment. I'm seriously ...