Comment on this cement job

[SwampDonkey]

Ok, so what do ya think of this job? Looks to me like it was poured in 3 days because it set between days. Look at all the seems for potential failures. To top that off, the wall was not level, it was bowed in because they used fasteners that were too long to tie the outside wall with the inside wall. Yet , the building inspector passed the job.  Now isn't that a lovely mess to do for new home owners?




Now tell me something....


What kinda load will this support?  

[beenthere]

Looks like the concrete may have been made on the site with a small mixer. Does it leak at the 'joints' ?

Can't tell what the grade stamp is on the 2x4 lower chord, but if it has strength in tension, the 'joists' may support what is expected of them. Is the floor springy, or not?  I wouldn't be too excited about that wall. Who is ending up with it? family? friends? you? Not that it makes a difference.
Also, can't tell what the King beam is made up of, and if that is your reference to your support question.

[ADfields]

Well if it's reinforced right and water proofed right it should be fine.   But with that kind of workmanship I would not count on the other stuff being right.   The truss load should not be reduced from cutting the bottom plate at a support beam like that but I would still like to see that free end tied off somehow.   Both things tell me the builder just don't give a DanG about their work and I would not use them, no matter how cheep they are! :-/
Andy

[Furby]

I don't know if you have ever been in a large warehouse or a simular building, but the metal roof trusse are made that way.
I belive that the idea is the bottom beam of the truss/joist is just to strenghten the long span. The load is transfered by the webbing back and forth. As long as the truss/joist are installed right side up, and not cut at the wrong spot, the are just as strong used this way.
This is just my understanding of it, I have offten wondered if it was true.

As for the concrete, it should be ok, but yeah, LOW quality workmanship!

[SwampDonkey]

The cement was poured by a readymix company. The trusse as you notice coming into the carrying beam is not toed into the beam at the bottom. With that being said I can't see how that the top 2x4 can carry all the load. It kind of reminds me of a fellow hanging onto a ledge by the forearms and his feet are searching for a ledge below to get footing into and it isn't there. Eventually the guy is gonna run out of strength.  The floor is not springy, yet.

Lumber grade on trouse

[SwampDonkey]

There was a whole square of birch flooring that wasn't properlly dried before it was finished and bundled for sale. Took 10 months to get that replaced. Some of the pine doors warped from improper drying, had to be redone. Obviously some carpenter cutting corners with air dried lumber. I don't think the garage was properlly insulated cause its hot in there in the summer. In my garage its cool and I have a 100 year old house, which is insulated.

[pasbuild]

The floor truss should be rated @ 90# per sq. ft.
Most forms are rated at 4 ft. per hour and on a large pour you can get a cold joint, a concrete vibrator is used to correct this during the pour.
As for the inspector it is there job to see that all code requirements are meet they do not inspect workmanship.
Because of this you have contractors that can't build a fence out building your home.

[slowzuki]

Swampy, is that dark looking composite beam thing supporting the engineered joist?  If so, it isn't supposed to be in the middle of a chord, should be under one of the lower brace connections.
Ken

[SwampDonkey]

Exactly Slowzuki. As you can see the putz sawed of the width of the carrying beam from every truss instead of having the carrying beam under the trusses at the bottom connector joint. So what ya got is a 2x4 on a flat edge supporting the floor and that bottom 2x4 of the truss isn't attached to nuthin, so it just adds to the load on the top 2x4 of the truss. There are 2 steal jil-pokes braced under the carrying beam. The way that's mucked up, a floor with 2x8's on edge would be 10 times stronger, with that carrying beam under the 2x8's. Hmm, somebody trying to tell me that picture is to code?  

[etat]

Gonna give my 2 and 1/2 cents worth here.  (inflation kicking in thats why the extra 1/2 cent) The concrete is different colors, that 'could' have been because it came in in different trucks, and each load was slightly shaded from the other.  IF so, the shades wouldn't effect the strength of the concrete.  Happens all the time, the shading part, if you mix runs of shingles on a house, doesn't affect the quality of the roof, but looks ugly. On a flat slab that whirly-bird thingy they use to smooth it all out evens out the color.

Trusses:  Trusses are a different breed of an animal than solid wood, (which I prefere, solid wood, or steel beams.  I honestly believe a 2/8 would be undersized for this application and would be weaker than the trusses. Depending on the span it could be much weaker.  As Furby said, steel bar joist , which these trusses are designed to duplicate, would be attached the same way, except the lower part, the part that would duplicate the lower 2/4 on the trusses where it bumps the beam would be non-existent.  It would be only the top part over the beam, and then angle back at the bottom, not attached at all to the lower part.  Doesn't look right, but that's the way they're designed to transfer the load.  I'm a thinking that in this application the load is NOT transfered to the lower 2/4.  

As I said, I've never liked that type truss, but they are stronger than they appear. .  The main reason I don't is if there's ever rot, or termite damage to the upper 2/4 at any point it will severely weaken the truss.  Also in the case of a fire, it will spread much faster with those type trusses, compare it to kindling. I've seen some pretty long spans of that type truss.  I'm not an engineer but I like to give my opinion.

[etat]

[etat]

This, as an amateur, is my idea of proper construction.  THere is  2 ten inch steel beams spanning 22 open feet over my living room, doesn't show one of em. .  Bolted to these beams are two, 2/10's.   Then 2/8 ceiling joists, with  14 1/2 inch 2/10's nailed between each joist. Underneath are 1/4 laths, glued and screwed on.  The ceiling itself in the living room is 4/8 sheets of oak cabinet plywood with grooves routed in on the underside to simulate oak boards.  The edges of the plywood have a lap joint routed in.  The plywood is attached from the TOP side only, it is both glued and screwed from the TOP, no exposed fasteners underneath.  One of the beams is off to the right of the picture.  There is 8 foot between the beams.  The braces to the left are over a supporting wall.  The cross braces were installed to prevent the rafters from racking during construction, at this point they are probably unnecessary, but aren't hurting anything so I just think I'll leave em. The white stuff stacked up there is crown molding that hasn't been installed yet, it's for the living room and kitchen. The top of the ceiling in the living room is 11 feet.  I expect none of this will sag in my lifetime. Attic insulation is incomplete at this time. Also radiant barrier, which will be attached to the underside of the rafters in incomplete in this photo. To the left of the photo is the area over the kitchen.  The attic space over the bedrooms and baths, not shown,  is complete, with insulation and radiant barrier. This is ALL my own design.  As a roofer I HATE working on springy, or uneven roofs. I expect none of this will sag in my lifetime.  

[SwampDonkey]

The color don't mean nuthin as you say, but that wasn't being questioned. It was the seems and the possibility it was run over 3 days, instead of one and maybe that's bad, maybe not. Time will tell in a couple years or so. You folks will have to come up here to the north and let the frost at them seems in your cement for 3 or 4 years, then give your opinion. We had a garage floor run 3 times and the cement had seems and it ended up crumbling like crackers in 3 to 5 years. Alot of folks are complaining about pour cement jobs up here. And one thing that makes the cement poor is the gravel used, some of what's used is too sour. That don't make scense since the parent material underneath is full of lime, which is in the water too.  hmmm I think someone's been telling me alot of bollock about the gravel, now that I think of it.

We hand poured a 100 ft by 50 foot consit floor over  3 days and it didn't crumble. Been sittin their since 1987. Only thing years afterward the bonehead that didn't think you had to open the doors up before ya back the combine out the door. Of well let's take the door with us.

What in the world you eatin today . I see the A1 sauce, must be T-bones. Or is that moose steaks. Thank goodnes it ain't grits. All I had was ham and turkey sandwich along with some fresh cauliflour dipped in ranch dressing. Slurp, yum.

[SwampDonkey]

By the way, steel beams will fail before wooden beams in a house fire.

[etat]

I gotta confession to make, them steaks wuz from fathers day!  T-bones and ribeye!  Started out they was 10 of em, folks wuz grabbing before I could get a picture.  

Fire ever gets hot enough to warp them beams I'm sunk anyways!!!

I once saw a documentary on house fires, and trusses.  Once they caught afire there wasn't much hope of puttin em out, as I said, burn like kindling. They said stick framing you'd have a better chance of puttin it out, and more time afore it collapsed.

[SwampDonkey]

Well you know these fast construction houses now a days. Two by fours, and aspinite. They'll never last like these old homes for over 100 years with rough sawn 2x10's , 6x6 , 8x8 and 10x10 beams and sills. One of my attics is 25' by 30' feet (inside space)and 15 feet to the peek, with a carrying beam spanning 20 feet over the garage, the other 10 feet is over the office. My other attic is over the 3 upstair bedrooms and bathroom and spans 25 x 25 feet (inside space). In the basement there is a carrying beam 10x10 spaning 25 feet with 2x10 floor joists toed into it and that beam is intercepted by another carrying beam at the centre. One steal jil-poke at the intersection. We don't have termites up here, just carpenter ants, which usually don't come in the house unless in firewood. Give them a little squirt of ant trap, stops that foolishness.

[SwampDonkey]

My father and grandfather used to hire a neighbor for farm work and once in awhile they would put up a shed or barn or an expansion on a shed. He wouldn't walk on a roof that he didn't build. He wasn't afraid of heights but he didn't trust no ones roof'n.

[SwampDonkey]

I totally agree with your take on the trusses in fires, but you know which part fails first? The steel reinforcing. In old houses like this one, they used fire stops so the fire didn't spread like karosene. Beleive me it takes awhile to burn through heavy timber framing.

450 F is pretty hot ain't it? And wood ain't even ignited yet until close to 500 F. Try it in the electric oven.

[Gary_C]

First on the concrete. The picture certainly shows sloppy workmanship, but it may be sound enough to last. It would require core samples to tell for sure. It is always good practice to pour forms that deep in stages so you do not get any blow-outs, but judging from the angles of the seams, that was not even done properly. As long as you don't see large areas that are honeycombed with a distinct line or crack between layers, it probably will be ok.

If the bottom chord (2x4) of the floor trusses has been cut through as it appears in the picture, the structural integrity has been destroyed. You can think of that truss as being similar to an I Beam. The 2x4's are the top and bottom flanges and the cross bracing or web as an I Beam is merely a spacer to hold the two flanges a fixed distance apart. When used in a horizonal application, the top chord is loaded in compression and the bottom cord in tension. If you cut that bottom 2x4 clear through, the only thing carying the load is one 2x4 laying flat. There is no way any inspector should pass that house if those 2x4's are cut through.

[SwampDonkey]

Exactly    But, there's so many people so buddy buddy, you wouldn't know what's going on in this business.

[etat]

Remember when I said I like to give my opinion.

Anyways, this is still bugging me so I did a bit of research.  In relation to floor truss systems I came across this bit of information.  There can be designed into the trusses such a thing as bottom cord bearing trusses, mid cord bearing trusses, and top cord bearing trusses.  In the case of a mid cord bearing, or top cord bearing, it would be ok to cut the bottom cord, if the top cord is properly supported. .  Also I found that on exceptionally long floor truss conditions a 'squash block', would have to be installed center ways. That could be very well the purpose of the center beam cut into the trusses, not to weaken but to prevent them from squashing.  Let's hope, and it is possible acording to my research, and full knowing that it might not be worth the whole 2 and 1/2 cents, that this design and application, is acceptable.  Although I found lots of information I did not find a picture of a top cord bearing truss.  I did find a picture of a bottom cord bearing truss, and a mid cord bearing truss.  The mid cord, with the bottom cut back would be the best  example of what I am describing.  

You'll notice that the top cord is sitting on a couple of 2/'s which the beam could very well replace.  

http://www.timbertruss.com/floortruss.htm

[ADfields]

The trusses are correctly installed and completely to the code hear.   If you place the beam under the bottom plate of that type truss it will just crush down till it fails or the top plate rests on the beam. That bracing will not hold a compression load at all, it has to be in tension, pulling not pushing.   If it were intended to have the beam under the bottom it would have a vertical support in the place that the beam sits under, this support transfers the load to the top and the bottom is just there because it's there.   Now I live in Alaska, home of 20% of the worlds earth quakes and 6 of the 10 biggest ever recorded so I would want the bottom ends tied off.   Like it is they could roll on their side and fail in the right quake movement.  Also they would pop the screws threw sheet rock if it is hung from them like they are I bet.
Andy

[etat]

AD, I agree with EVERYTHING you said!!!!!

[Bruce_A]

The concrete is held together with a glue called cement.  A good finisher can redo anything that may be wrong with that wall for less than fifteen hundred dollars american. The trusses appear to be what is usually called a web joist.  They are supported by the top cord.  I don't believe they were cut to put them in place, but are built this way instead.  Most commercial buildings built in the lower states use a similar type truss and have for many years.  Try to get a look at a safeway store during construction or remodling and you will see what I am talking about. If this was done according to the uniform building code as it should have been, it will outlast solid wood construction. And is stronger to boot.

[SwampDonkey]

Well the floor hasn't collaspes yet and its not springy. Good sign.

I'm going to research it a bit from here

Canadian Wood Counsel

You folks in the US will find the info here pertanent and there are links to US sites. Well off to the woods 'til later.    

Thanks for all your knowledge and input, Trusses aren't my thang.

[slowzuki]

Well, that depends now!  Slap a couple of layers of 5/8" fire rock and the steel will be good for better than 2 hours.

My day job is as a fire protection engineer which mean a lot of things but the funnest is fire investigations!  

Swampy is right, unprotected steel in the thicknesses small building are built with won't last near as long as heavy timber or even some light wood framing.

Now in big buildings you can get some huge steel that can absorb so much heat it will outlast the fuel sources in the area.

When I was working on an investigation of a large plywood mill fire, there where a bunch of differerent types of construction to look at.  

The masonory kiln area was still standing but you could pull it apart with your hands.  Some of the small leantos etc were ok (well, standing) because they had aluminum roofing that melted off and vented.  The main building had glulam trusses that stayed up a long time and didn't have any delamination.  The 2" t&g roof deck (spruce I think) was completely reduced to coals.  The steel framed building stayed upright as the huge doors were open to vent the heat through it.

Nothing quite like fire spread in a veneer mill, would have been scary for the fellows working there.

By the way, steel beams will fail before wooden beams in a house fire.

[ADfields]

I've been told that pound for pound wood is stronger then steel in compression and the other way round in tension.   I know from blacksmithing 800 degrees in mild steel is the start of red hot, around 400 degrees it's getting real bendy, it's burning at around 1300.   I wonder what the flash point of dry spruce is.   We had a old log shack down the road burn, the floor and roof went but the log walls are just a bit black.   That was with out any fire fighting on it at all, just containment.

[beenthere]

AD  Interesting point about strength of wood vs. steel, but that comparison to steel might ( I think) be the other way around, i.e. wood is stronger than steel (pound for pound) in tension (and that even needs to be qualified to be straight-grained wood free of any defect, and measured in tension parallel to the grain).  Across the grain, many species, such as red oak are pretty weak in tension. Those woods are the ones that are easy to split with a splitting maul when making firewood.

Measuring the tensile strength of wood is difficult, and special grips and specimen shapes are made to test wood.  I remember seeing huge machines set up to test full size lumber specimens, and the grips were huge and often crushed the wood (compression) under the grips before the specimen would break in tension. And then, it would break where there was a knot or was squirrely grain around the knot.

[ADfields]

I think I have it right, a dry 2"x4"x8' spruce will come in about the same poundage as a 1-1/4"x1/4"x8' hot roll steel.  Off the top of my head without looking it all up.   The 2x4 would hold me at center span and I don't think the steel would.   Maybe a steel stud is a better choice but I don't think that would hold up much better then the hot roll.   You are right on about selecting wood.  
Andy

[Egon]

Perhaps a few uneducated  comments on the beams/trusses.  Simple Beams are designed to meet shear, bending moment and buckling requirements. Shear is usually greatest at the support, Bending moment at midpoint and buckling at midpoint. Usually bending moment is the dominant requirement of the beam design. This would indicate the placement of the trusses as shown for the layout of the truss will be correct.

On fires:  Large solid wooden structural components fare well in fires. This happens due to a layer of charcoal forming on the exterior portion of the beam which cuts off the oxygen supply to the fire. Metal structural components lose strenght when heated and may be insulated for fire protection.  

Egon

[etat]

So....in the case of my 22 foot beams wrapped with wood, all but the top and bottom flange, seems like I'm getting the best of both worlds.  Ten inch beam, 2/10's bolted to each side, and additional wood fastened to that, Maybe I'm gonna be ok.



By the way, we put them beams up there by 'hand power' and quite a bit of 'southern ingenuity'! .  Had us lotsa fun that day!  Worst part was when I put em up I decided they was 1 foot too high.  It was a LOT harder lowering em than it was puttin em up there to begin with.

[SwampDonkey]

 

One of them fella's that's got to do everything twice eh CK?

[ADfields]

, no doubt you got enough beam.  Now do you have enough wall or post to hold that big thing up.   Make for a bad day if that knocked you in the head as it fell.

SwampDonkey, I wish I got most stuff right in just 2 tries!
Andy

[etat]

AD, I'm a hoping it orghta  stay there, lots and lots of doubled up wood under them beams.  Not ever been earthquakes around here but occasionally we get some straight line wind, and every once in a while a tornado sets down around here somewhere.  I wanna be as ready as I can be. One end the wood and floor is sitting and bolted to  the main foundation of the house, which is probably dug dang near deep enough to hold up in yall's high frost conditions, and got some BIG rebar buried in the concrete.  Seems sometimes them big construction types working haul bunches of that stuff to the dump, and I've got a good friend who's in charge of burying it! It don't always get buried, he saved rebar for me off and on for 6 or 8 months, before I started the house.  Had to heat that junk with a torch to bend some of it!  The other side's I dug holes about 3 foot diameter and as deep as the backhoe on my tractor would dig em, throwed some steel in there, filled em full of concrete, and then cemented doubled up concrete block pillows, and filled them full of concrete.   In fact they's a bunch of them homemade pillow blocks under the house.

There probably ain't enough space on this forum to list all the stuff I've done, and redone, and redone!  The things that I know that I'll never get perfect, I'll just learn to look at it as character!

[SwampDonkey]

 

CK:

I spend a good part of my time lookin for the tool I just sat down.  

And I never read directions, so them home assembly jobs I do over 2 or 3 times so I don't forget next time.