Do the numbers work? The concept is 2x4s on 16″ centers for exterior walls, then horizontal 2x2s on horizontal 16s on the interior.
This versus 2×6 walls on the same centering.
Supposed energy savings.
The Mooney wall will get 5″ of dense-pak cellulose, and the 2×6 wall will get 5-1/2″.
Framing costs will increase with the Mooney wall due to the additional labor to fur up the inside walls.
Material costs per square foot of exterior wall will be about equal, I think. My cost for a 2x4x8 plus a 2x2x8 is a nickel more than one 2x6x8. Even though I won’t have doubles at wall tops in 2×2 versus the double plates of the walls, or kings and jacks at windows in the 2×2, I will want to throw in some extra beef to the 2x furring for baseboard and window trimming.
Edited 1/13/2004 7:33:49 AM ET by Mr. Micro
Replies
Youve got it down pretty much except the bottom and top chords are to choice of the trim schedule . Provideing solid blocking at base board and crown . If the window and door trim schedule were wide also , viola. Its also a way of picking over lumber with out sending it back or using it with objection. The lumbers only requirement be that it be the same thickness . If you are building a ballon wall then you can pick the best from the start and have favorable results . Lathing is also a way of disposing of lumber over runs from the past job and using any thing 2 ft and over . From that approach its a savings way to quality.
Tim Mooney
Will the 5" wall thickness be costly for window jamb extensions?
since u axed... the answer is yes....
or ..
no... .
. will your customer be happier with deeper windows ?.. is the labor more for a 1/4" extended jamb or an 1 1/2" extended jamb ?
depends on what you are trying to do.... will it cost more? you bet..
is it worth it ?...... to me. yes.. maybe not to u ...
Mike Smith Rhode Island : Design / Build / Repair / Restore
Mike pretty well covered it . Where I live it wouldnt cost too much . Remember I said that , youll keep running into it ; locations change a bunch. Mike lives in a very rich town so yea its gonna cost um. When I show up in his town , Ill probably stick out like a diamond in a bulls butt. The differences are major.
Tim Mooney
You get a pretty good thermal break with the framing this way. Less conduction. Trying to imagine a way of calculating the cost/benefit ratio with the extra labor. That would be tough to do.
Another thermal break method to consider is adding a layer of foam board.
Once saw a home built with a 'double wall' for a thermal break and a 12 inch cavity. Expensive, but I admired the overkill, and the substantial 'feel' of those deep window and door openings. Sort of castle-like.
How do you dense pack that wall? The stud cavities are open top to bottom, what am I missing?
Joe H
What do you do to a 6 inch wall?
The dense pack is blown flush with the stapping , so those members give support plus a solid 2x what ever you need for the trim schedule at bottom to keep it packed in at floor instead of crumbling in an open bay.
Id be more than happy to take notes from your expertise. "Am I" missing something? Im serious about the last two sentences . Do you do interior cross blocking ? If you do its still a step that can be done to either wall, but the cross members help to hold the dense pack. I really like the two by at the bottom all the way through.
Tim Mooney
Edited 1/13/2004 11:11:08 AM ET by Tim Mooney
Tim, am I missing something? I meant what is keeping it in the studbay? Are you using mesh?
I'm picturing the studs being open between the strapping, cells going through there into the adjoining bays.
Or, if there is mesh on the studs, then it's 3 1/2" of cells with the 2x strapping over the mesh?
I am obviously missing something here, but what?
Joe H
i think i may be able to clarify here a little. joe thinks you are dense packing dry tim, and tim is talking about dense packing wet with a rotary scraper knocking down wet dense pack flush to outside of furring.
the method outlined in the taunton weatherizing and insulating book for pros by pros (good book, i learned a lot but then i am basically a glorified framer) was to leave a gap in the drywall at the center of the wall horizontally, and fill the say 3" gap with a strip of 3/8s drywall and then mudd over entire area. after drywall is in (except for strip) you blow in dense pac dry through the 3" hole you have in each stud bay. I think thats what joe is thinking about.
did i get it guys? and if i am correct is there some sort of reward? do i win a prize? can i at least get you each to be a reference for me when i apply for my next consulting position?
Skids does indeed win a prize.
Andy, a free subscription please.
Didn't think wet could be installed that deep at one time.
Joe H
the mooney wall uses dry blown dens-pak cells.. blown thru insul mesh which is stapled & GLUED to the FACE (warm side ) of the horizontal 2x2 furring (1.5x1.5)...
the only difference between this and the Regal Wall is the addition of the 2x2 horizontal furring..
the process is.. frame... horizontal furring.... rough -in plbg & elec.... inspect.... isul -mesh stapled.. pulled tight & glued.. let cure overnight... dry dens-pak the next dayMike Smith Rhode Island : Design / Build / Repair / Restore
My cellulose guy uses a "water add" process that adds enough beef to the mix so that stud bays are blown and are self-supporting. A tool that looks sort of like an old reel mower is used to saw-shear off the protruding excess cellulose. The finished product is cellulose right out to the stud line, nice even density.
All the stuff that's sheared off goes right back in the hopper. The attic is blown dry, of course.
I'm presuming he could blow a Mooney wall scheme, but I am going to ask him.
Attached is a pic of what I believe we are talking about. I drew it to be able to communicate with my cellulose guy.
sounds like a winner , gene.... your insulator is gonna like this new twist.. especiallly the little touches like room behind the electric boxes... yada , yada , yada.... AND
the horizontal furring is gonna help with the vertical support of the wet blown cellsMike Smith Rhode Island : Design / Build / Repair / Restore
Mike, then come's the drywall stage,,, do you hang your drywall, with the 4' width going left to right ?,, or??. I've been thinking about the Mooney wall, I sure like the ideal, you say it's a better wall,,, insulating/comfort/cost savings etc and I believe you. The last new home I built was a post and beam w/ Straw Bale wall system. The walls ended up being 24" thick (3 wire bales). The one before that was 2-- 2x6 exterior wall system, we basically framed two 2x6 walls on the exterior, and had the insulator "wet spray" celulose. On both these homes, the people who live in them,, well, they love em, easy to heat, quiet, nice window and door returns, and a little different then the norm. Be safe out there Jim J
yes... my plasterer hangs horizontal..
hey, this aint the same as your double wall... or your haybale wall... (fantastic ) but..
it's a pretty good cost-effective wall system that i think is superior to a 2x6 wall..
our house is old tech... 2x4 exterior with cells.. 1" airspace.. and 2x3 interior with FG..
i'd rather have the mooney wall.. but wysiwyg...Mike Smith Rhode Island : Design / Build / Repair / Restore
The idea is from a cost approach all the way to competing with a 6 inch wall plus adding more than a 6 inch wall offers in other areas other than 1/2 inch of insulation. You mention drywall and that was one consideration. The big boxes sell 8 ft drywall on cost leader all the time along with studs and used to be blandex . Full stocking lumber yards [contractors store] cant or wont sell drywall per sq ft as cheap as the big boxes sell 8 ft stock. Last time I bought it was 5 cents per sq ft difference . I haul it and hang it by myself standing up . Viola , Ive got money to the bottom line because I havent paid a stocking charge or a delivery charge . Now Im up 8 to 10 cents a foot savings just to the lumber yard and save money hanging it with out paying that out . I have the ceilings hung with 12 ft stock . Any way hanging 8s vertical on horizontal strapping is for ever more fast . On walls that are higher use a full two by width to join the top peices .
To note again that Mike builds and remodels high end and all Im interrested in is economy.
Tim Mooney
In my little building jurisdiction here, code requires 2x6 walls be used in exterior walls, so for me there are three questions:
1. Can I get a 5" mooney wall structure approved? I am pretty sure I can talk Jim into it.
2. What will it cost me, versus standard 2x6s on 16"? Probably 4 framers working 1-1/2 to 2 days, to detail out the insides with 2x furring. That is conservative, I think.
3. This is the big one. Is it really worth it?
gene.... only you can answer those 3 questions...
i think anything you spend on the furring, you'll get back on your interior trim Mike Smith Rhode Island : Design / Build / Repair / Restore
Figgure your big box prices on good studs , economy studs , 8 ft drywall to the building store you are having touble with. Lowes delivers free too on an AR account . You have to gather your prices . There will be some money left on the table .
Tim Mooney
From a drywaller's point of view, it is more efficient to run the board the long way. Stand up board eliminates butt joints, however you wind up with about 35% more LF of joint - same thing whenever you cross furr a ceiling. 12' horizontal is also faster to hang than 8' stand up.
Your post was a little confusing to me . Ill comment on it anyway in statement .
The drywall hanger makes more money hanging 12s horizontal on studs when a crew is present. One hanger by himself can match the time standing up with horizontal members to screw to because its easy to follow screwing or nailing pattern . Every horizontal member is the same measurement around the whole envelope. Thats where speed is gained standing it up and being able to use one man with less loss motion of using two. I want to be sure to mention too that if you are comparing hanging to the studs, horizontal is the fastest way.
The taper makes more money on vertical but has to work harder doing it . [lots of bending] Butt joints are eliminated which normally take at least an extra coat. There are more running ft of joints to cover standing up , but all those are done with automatic tools which eliminates some of the difference . The butt joint is one that demands attention to the eye and hand tools therefore costing some extra time . Vertical joints are ran automatic.
Still , at buying from the box store with a savings of 5 to 7 cents , money is gained standing it up even on interior walls to studs.
Theres a chance that the hanging price could be bid to you at the same money if you hired it done.
Tim Mooney
Do you cut your own 2x2's? The only ones I see at our lumber yard are more bent and twisted than a spammer's morals - and the ones at the big box are worse. It would seem like metal resilient channel might be a better choice, although the readily available ones that I have used are shallower - although I assume different depths could be ordered.
I build for my self meaning that the house is mine at the end and sometimes remains mine . Thats a different scenario of someone building for someone else . OK? The less money I have in a project the less interrest I pay and the more room for profit I make if the building becomes my rental . If its a spec house I will also have less money in it by taking money saving tactics . If it doesnt sell it will be a rental , or maybe a rental till its sold . Anyway you slice it i need to lower the cost to the bank to bare bones . So my situation probably is different .
I rip it all and also buy 4 footers for .25 cents a peice and rip them. Sometime I get a 4 ft 2x12 for .25 . The yard cuts up lumber that doesnt sell in 4 ft sections from 2x4 to 2x12. I use all of it I can . I dont use bowed lumber but crooked in 4 ft is fine . Ive got a 12 inch craftsman 3 1/2 hp that stays plugged up. Noone wants to steal it .
Tim Mooney
Hi Mike. So do you fill in the studs where the elec boxes go? Or have the electrician do it? What about an open stud wall like between garage/house. Do you mesh both sides?
Does it make any sense to rip 1/4" wood strips and staple them on to the studs over the mesh instead of smearing the glue on?
jim
jim.. we do all our own insulating..
if it's an open stud wall... usually we'll rock one side... but we 've done it with mesh too.. ( which is a spun fiber )....
the 1/4" strips might work fine... but i like the staples and glue.. and no voids.. this system is really tight .. might be hard to get it that tight with the 1/4" stripsMike Smith Rhode Island : Design / Build / Repair / Restore
Mike, when I asked this....
"Hi Mike. So do you fill in the studs where the elec boxes go? Or have the electrician do it?"
I meant to ask, Do you nail short lengths of 2x2 to the studs to make them even with the strapping. I guess obviously you do. I'm doing an upstairs remodel to an old house now, I think I will use your insulating method. Could you give me a link to the company that makes the mesh you use? thanks, jim
jim... the boxes can get screwed to short pieces of 2x2 block and nailed to the face of the stud
i bought the spun fiber and the latex glue from Regal Industries... i can get the same spun fiber from my local cellulose supplier.... InsulMart.. but they didn't have the glue.. the glue comes in gal. cans and looks almost like wallpaper paste
here's a link for Regal.... call the number and talk to one of their salesmen..have your credit card ready..
http://www.regalind.com/regal_wall.htm
nice site.. take a look at their technical discussions..
and don't buy the 1/4" mesh.... unless you like eating cells..
here's the old system.....the spun fiber is nicer..
BTW... see the copper plbg fittings.. they reduce the blower to 1" for really tight places like the box headers we use.. most of the blows can get all the density you need with a 1.5" nozzle... and you can experiment with different fittings .. you want a compromise of speed and density... and as few clogs to deal with as possible
Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 1/16/2004 12:48:04 PM ET by Mike Smith
mike,
do the rockers glue their board to the insul-mesh ? will drywall adhesive stick to it ?
carpenter in transition
tim... they can ... and it will..... BUT
we don't use no stinkin glue with our blue board and skimcoat plasterMike Smith Rhode Island : Design / Build / Repair / Restore
I believe its done after further reading . Skids gets a consulting referral and Mike was the real promotions manager on that gig , so his fees are on retainer . He added the mesh too , which is better.
Tim Mooney
I'm picturing a homeowner twice removed from the original trying to find a vertical stud to hang his TV on in his bedroom. Ain't he in for a shock. A whole lot of "WTF's" are gonna echo around those horizontally strapped walls. But he'll get over it.
Nobody asked but...
My calcs. say that that the Mooney wall is an R value of 14.9. while a 2x6 wall is 16.3. This is with DP cell, R 3.4/". The R per " works to almost the exact same.
Of course, the mooney wall has greatly reduced thermal breaks, is great for trim and other elements, and as Tim is submitting, saves money in the other phases.
Jon Blakemore
And for comparison, here are the R-values for SIPs of various thicknesses. As you can see, barring factors such as thermal bridging, air infiltration, sheer strength, speed of construction, etc., the Moony wall compares favorably with 4 1/2" sips at a little lower cost. SIPs are still my first choice but the Mooney wall is the best I've seen in more conventional construction. I count it among the top five best techniques I've learned on this site.
SIPThickness
R-Valueat 75 F
R-Valueat 40 F
4 1 / 2 "
14.9
16.0
6 1 / 2 "
22.6
24.3
8 1 / 4 "
29.3
31.6
10 1 / 4 "
37.0
39.9
12 1 / 4 "
44.7
48.3Kevin Halliburton
"I believe that architecture is a pragmatic art. To become art it must be built on a foundation of necessity." - I.M. Pei -