Framer / foundation question

[Amber_Goldman]

Ok you guys in the field..........how do you like it....

Condition - 2x wood framed foundation, singles story, interior cmu piers (crawl space not piles) with continuous block wall, nothing big & glamorous......for pains sake lets call it a 2000 sq.ft ranch....... do you prefer the floor joist to hang from the beam (making the beam & joist flush) or do you prefer the beam to run below the floor joist (setting them on top). I know different circumstances mean different applications.........but what’s the norm.... what do you like to do in the field

Amber

[ChiefChris]

Amber.
I prefer to bear the joists on the beam rather than notch them into the beams. Notching them into the beams is a sure fire way to garuntee a squeaky floor. The joists would have to be cut exact every time to fit the beam flange. If one is slightly short in the notch cut you invite sqeaks. And, if you're in a crawl space - it matters not that the beam is below the joists. It makes a slight difference if the homeowner wants to finish the basment....but for a crawl....no matter.

It's also not as much of a headache for the framer.

[Amber_Goldman]

I'd also like to add .........this to my list of how do you like it.....
Girder/beam do you prfer 2x's or timbers (6x6 or 8x8's) whats easy, whats cost effective,

[ChiefChris]

When deciding between an engineered timber strand beam (LVL, Lam, or the like) and standard lumber...there are factors that play into that like span, total load, clear opening, mechanicals.

I use both engineered & SPF lumber depending on the application. It's not always a matter of preference, but of necessity to the situation.

If you can give a specific application & details of the net forces applied in the situation - I can certainly give suggestions. But not a general rule of thumb....

[Tim O'Donnell]

the floor joists on top of the beam are easiest and fastest...both for framing and for mechanical, plumbing and electric if they need to be in the joist bay

[Amber_Goldman]

Standard 2x framing no engineering (required by code) no span greater than 6feet (pier to pier) single story 8' ceilings simple rectangular (lets say 35x60) ranch style house. I'm just trying to see...... is there a general preference when 2x girders are more than acceptable but timbers are an option as well. Do you always choose spf lumber if it meets the span & load or wood you use timbers because theres less to handle. I know this is vague..i'll take a vauge response. I just hate to draw something that can be done for less, easier application or save the customer time & money (not quality or structural integrity). I don't usually get in the field and my invovment stops after I finish the drawings...I guess I need to get out more.

Amber

[ChiefChris]

Ok...From what I can gather....

I would use a W8x18 steel I beam in your crawl/basement for the main bearing even if it is only a 6' span....it's in the crawl = moisture and other unwanted entities will be there...ALTHOUGH, you could use an engineered floor beam - such as a 5¼"x11¼ ParaLam beam or LVL's...but that's a bit non-standard.

For headers up to 6' with a normal overhead bearing I would just use a (2)2x10 SPF header with Double "trimmers" (jack studs). Over 6' (to 14') I will tripple the 2x10, or use a 3½" LVL header with tripple jacks.

There are times when I need to use a hem/fir material...mainly in roof spans for hand-framing. Or if the floor joists are too long of a span for SPF. Otherwise, I always use SPF. A roof rafter of 2x10 or 2x12 over 18' long will be Hem/Fir. I like to use Hem/Fir (at 12" o.c.) for a floor joist over 16'.

In your hypothetical situation I would use the W8x18 steel, I assume one beam in the center giving a 17' span - you can use Engineered joists (TJI's) that will span 17'-2"...2x10's for header openings.

[juststeve]

Amber-

Multiple ply 2X beams are normally a better solution than a single 6 or 8 inch wide beam for a few reasons.

1. Multiple ply 2X beams cannot have checks and voids that run across the width of the entire beam. Comparing the same sizes under the same conditions a multiple-ply beam will bear more load.

2. In my part of the country it is impossible to find 6 or 8 inch wide beam that is KD.

3. Framers usually prefer lifting individual plies of 2X into place and then laminating them rather than hoisting a 6 or 8 inch (green) timber into place.

Hope this helps.

[ChiefChris]

Steve,

I beg to differ. I prefer to use solid ply beams when using engineered lumber (LVL's ParaLams etc)....rather than nailing together 2 or 3+ plys of 1¾" LVL's. My framer actually prefers that too....why?

1. The single ply at 5¼" is stronger and more structurally sound than a 3-ply 1¾"
2. The framer doesn't have to use 4 boxes of nails.
3. The framer has muscles and ladders to heave it up there (I help too).

I have used ParaLams & PSL beams up to 7¼" wide and 18" high. Even a 3½"x30" beam....they're out there. And sometimes, necessary.

[Amber_Goldman]

This is interesting..........I've used both the 2x beams and 6 & 8" beams but, steel in this area (south Alabama) is not generaly used as a beam in residential foundations (unless its big and mighty) - Hummm you guys got me thinkin.

Amber

[ChiefChris]

When we say a 2x beam - I assume we are talking about nominal lumber. When I say a 2ply - that's how many are nailed together....(like toilet paper, ply)...

I always use steel in the basement (& crawl) for the main structural beam of the house. I do use steel often in the first floor walls - for garage door openings, bearing second floor joists & roof etc.

I use engineered lumber for structural beams and headers within the walls and floor systems. I do sometimes have 7¼" beams in the floor systems parallen with joists for bearing of the second floor load bearing walls.

Below are 2 files of a first floor & second floor joist system.

The orange is 2x10 joists. The green is ParaLam floor beams (flush in the joist system), and the light blue on Image 1 is the steel in the basement.

[juststeve]

Chris-

You are correct regarding engineered lumber, but I was thinking solid sawn. Voids and checks are not (or at least should not be) a problem with any engineered product, so that should not apply.

While a single 5-1/4 engineered beam is stronger than (3) 1-3/4" plies of the same depth laminated together the same is not true of solid sawn.

Regarding lifting beams in place - your framers must be both young and strong. Mine reguarly gripe about hoisting PT Parallam beams in place (I use them for decks). Here in New England we have fewer young strong framers than we once did as less people opt to go into the trades.

You are completely correct about the four boxes of nails. Nailing (or worse, bolting) is a pain in the neck...or even lower.

[Amber_Goldman]

O.k...... I was thinking sawn & solid here in this hypothetical house. this is what seems to be whats used around here. I do use the other but not as a norm. so........I see both 6x's & 8'xs and double & tripple 2x10s & 2x12s .......which one do you or your framer prefer to use & I guess we all like to put the joist on top unless we need the room below. You guys are great! I appreciate all the thought you have put in this question.

[ChiefChris]

Steve,

My framers are strong, no big bellies on my framing crews...that's true...young is relative I suppose. They don't complain about lifting the beams - they do grunt and groan a lot, but no complaining. That's the way I did it too (when I was framing)...I would rather take the extra couple of minutes and sweat to lift a heavy beam than rent a lift or crane...to me, a waste of $$. We have even hand set ridge beams at 5¼ that span the entire run of the ridge...lots of groaning there, but we get it done...

[slatta]

Amber

the framers I have been working with have been wanting it done with out any post and beam at all

we have been doing 2 x 4 pony walls on strip footings for years in the northwest

I try not to use any steel beams if I don't have to, up here its a no no