Questions tagged [engineering]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
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. ...
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 ...
27
votes
9answers
278k 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 ...
12
votes
7answers
62k 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 ...
6
votes
4answers
43k views

How strong are bolts compared to welding and what qualities to look for in foundations?

I'm planning on building a home climbing wall, made from a mild steel subframe. It will probably be around 10 feet tall approx. I was thinking along the lines of using mild steel angle, cutting to ...
5
votes
3answers
28k views

How can I calculate the load capacity of a platform?

I'm planning to build a very basic bed frame, but I'm not sure what size lumber to use. I was thinking of building the entire thing from 2x4s (legs would be 4x4), but I'm not sure if this will be ...
4
votes
15answers
18k 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 ...
4
votes
4answers
8k 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 ...
4
votes
4answers
935 views

Air conditioning on a shoestring budget

Without purchasing expensive air-con units, or solar panels - and the associated moutings and electrical paraphernalia, is it possible to create a temperature difference of 10-20 °C using materials ...
4
votes
3answers
7k views

How can I support a large aquarium built into a wall?

I have a wall that goes 3/4th of the way to the ceiling between my living room and dining room. I would like to put a fish tank in it, spanning the length of the wall. I have the engineering skills ...
4
votes
1answer
2k views

How much weight should a deck of a given area support?

How much weight should a deck of a given area support, either according to building codes or convention? In my local (Massachusetts) building code, I found the answer for floors (40 lbs/ft2 live load)...
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 ...
3
votes
1answer
1k views

What exactly is magnetic drilling equipment?

What puzzles me is a term "magnetic" in the context of Magnetic Drilling Machines by Euroboor (for example).
2
votes
2answers
623 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 ...
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 ...
2
votes
2answers
768 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-...
2
votes
1answer
2k views

How would I replace 4 posts and beam holding my covered patio with 2 posts?

I have a covered patio that extends 10' from the house towards the yard/pool and has a width of 30-33'. The covered patio seems to be part of the roof, I even have access from the attic as we ran some ...
1
vote
2answers
495 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 ...
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
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 ...
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
2answers
932 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
160 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
2answers
469 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 ...
1
vote
2answers
1k 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
108 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 ...
1
vote
1answer
298 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 ...
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
2answers
214 views

Attic was built to be living space in 1945, but are the trusses strong enough to keep doing so?

I have a Cape Cod style house that was built in 1945 with an attic as a living space. The trusses are 2x6, 16" apart, and don't span more than 15' across. Do I need to reinforce these trusses or ...
1
vote
1answer
122 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
1answer
324 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 ...
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
1answer
276 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
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
1answer
700 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 ...
1
vote
1answer
166 views

Weight distribution on library ladder?

I have a very tall galkey kitchen, with cabinets run to the ceiling. A library ladder would be an ideal way to utilize this space. I have the skills necessary to fabrcate what I need, but I don't know ...
1
vote
0answers
63 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
0answers
107 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
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 ...
1
vote
0answers
569 views

How do I hang a 500lb bed swing?

Could someone please tell me what kind of support is needed to hang a 500 pound porch bed swing? The 500 pounds also includes the weight of people on the swing.
0
votes
3answers
59k 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 ...
0
votes
2answers
1k views

Replacing a spanned “beam” with a cantilevered beam

I have a support post in my attic that is holding up one side of a minor ridge beam. The post is sitting on two 2x6s on their backs, and which span 20 inches. Yes, these 2x6s are not on edge -- they ...
0
votes
1answer
72 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
1answer
54 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
320 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 ...
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
2answers
355 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
18 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
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
1answer
91 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 ...