Any Carpenters in the house.

[OLE RASPY]

I got a question. Im planning on building a 30' by 30' garage next year.Im getting my ducks in a row right now.I got everything figured out except a vapor barrier,housewrap,or whatever.I am biulding my walls on 16'' centers 2by4's and using trusses instead of stick framing the roof.I will be putting up ribbed metal on walls and roof do i need to wrap the entire garage walls and roof before attaching my metal.I really dont want to insulate it but i might dunno yet but leaning closer to not.I have heard both ways dont wrap it and wrap it. And if i have to can i just use regular tyvex house wrap.Thanks.

[TurkeyScratch]

Myself, I would not worry about housewrap on the walls UNLESS  it might be a little while before I put on the metal. As far as the roof, if your putting on a decking before your metal and want an additonal barrier, velt paper would be an option. Velt paper would be an option for wall barrier also and cost less than Tyvex . 

[OLE RASPY]

Also forgot to add that i will be covering the walls inside with either some kind of paneling or ribbed metal.This is leading me to think if the metal does sweat there will be no air to get in to dry it out enough.Just me thinking though.Any more thoughts.

[stone road turkey calls]

put the tyvex on it will keep moister out and cut dowd on air blowing through, which could get cold with no insulation. also local code may require house wrap, you don't want some inspecter making you pull down all that sheet steel to rerap.
good luck

[Preacher]

Check into regular old tarpaper  its cheap and easy.   Pretty good mositure barrier.

[Mailman]

I think you would want to wrap it to keep moisture away from the wood studs and plates.

[lacountryboy]

Over the last 40 years I've done it and seen it done both ways lots of time and never saw a problem with either.  I would put foil faced bubble insulation on the roof at least if you think you might want to insulate later.

[OLE RASPY]

Might just have to use tar paper then.Sounds good.Thanks for the suggestions.

[OLE RASPY]

Myself, I would not worry about housewrap on the walls UNLESS  it might be a little while before I put on the metal. As far as the roof, if your putting on a decking before your metal and want an additonal barrier, velt paper would be an option. Velt paper would be an option for wall barrier also and cost less than Tyvex . 

I wont be putting down any kind of decking on the roof just trusses and 2by4's horizontially run think i should go ahead and wrap the roof to.

[gobblingghost]

I believe this what your looking for

Wall Covering
R703.2 Water-resistive barrier.

One layer of No. 15 asphalt felt, free from holes and breaks, complying with ASTM D 226 for Type 1 felt or other approved water-resistive barrier shall be applied over studs or sheathing of all exterior walls. Such felt or material shall be applied horizontally, with the upper layer lapped over the lower layer not less than 2 inches (51 mm). Where joints occur, felt shall be lapped not less than 6 inches (152 mm). The felt or other approved material shall be continuous to the top of walls and terminated at penetrations and building appendages in a manner to meet the requirements of the exterior wall envelope as described in Section R703.1.

Exception: Omission of the water-resistive barrier is permitted in the following situations:


1.   In detached accessory buildings.
2.   Under exterior wall finish materials as permitted in Table R703.4.
3.   Under paperbacked stucco lath when the paper backing is an approved weather-resistive sheathing paper.


Top Previous Section Next Section     To view the next subsection please select the Next Section option.

  View ICC-ES Reports/Listings for:   
072100 Thermal Insulation
   ESR-1615 NCFI Polyurethanes
   ESR-2072 Bayer MaterialScience, LLC
   ESR-2222 Proactive Technology Inc.
   ESR-3210 Demilec (USA) LLC
   ESR-3212 Service Partners, LLC

072500 Water-Resistive Barriers/Weather Barriers
   ESR-1615 NCFI Polyurethanes

Visit ICC-ES Website SECTION R318 MOISTURE VAPOR RETARDERS



R318.1 Moisture control.


In all framed walls, floors and roof/ceilings comprising elements of the building thermal envelope, a vapor retarder shall be installed on the warm- in-winter side of the insulation.


Exceptions:




1.   In construction where moisture or freezing will not damage the materials.


2.   Where the framed cavity or space is ventilated to allow moisture to escape.


3.   In counties identified as in climate zones 1 through 4 in Table N1101.2.

[OLE RASPY]

I believe this what your looking for

Wall Covering
R703.2 Water-resistive barrier.

One layer of No. 15 asphalt felt, free from holes and breaks, complying with ASTM D 226 for Type 1 felt or other approved water-resistive barrier shall be applied over studs or sheathing of all exterior walls. Such felt or material shall be applied horizontally, with the upper layer lapped over the lower layer not less than 2 inches (51 mm). Where joints occur, felt shall be lapped not less than 6 inches (152 mm). The felt or other approved material shall be continuous to the top of walls and terminated at penetrations and building appendages in a manner to meet the requirements of the exterior wall envelope as described in Section R703.1.

Exception: Omission of the water-resistive barrier is permitted in the following situations:


1.   In detached accessory buildings.
2.   Under exterior wall finish materials as permitted in Table R703.4.
3.   Under paperbacked stucco lath when the paper backing is an approved weather-resistive sheathing paper.


Top Previous Section Next Section     To view the next subsection please select the Next Section option.

  View ICC-ES Reports/Listings for:   
072100 Thermal Insulation
   ESR-1615 NCFI Polyurethanes
   ESR-2072 Bayer MaterialScience, LLC
   ESR-2222 Proactive Technology Inc.
   ESR-3210 Demilec (USA) LLC
   ESR-3212 Service Partners, LLC

072500 Water-Resistive Barriers/Weather Barriers
   ESR-1615 NCFI Polyurethanes

Visit ICC-ES Website SECTION R318 MOISTURE VAPOR RETARDERS



R318.1 Moisture control.


In all framed walls, floors and roof/ceilings comprising elements of the building thermal envelope, a vapor retarder shall be installed on the warm- in-winter side of the insulation.


Exceptions:




1.   In construction where moisture or freezing will not damage the materials.


2.   Where the framed cavity or space is ventilated to allow moisture to escape.


3.   In counties identified as in climate zones 1 through 4 in Table N1101.2.

Daggone is that english.   Thanks man for the info i fully understand that.I will be wrapping it but dunno bout the tar(felt) paper yet.I dont want to smell that stuff in the garage.I got my roof reroof about 3 months ago and i can still smell that tar paper and thats outside.Thanks again for the info.

[woodwzrd]

I am a builder and have taken off a lot of old siding only to find the tar paper or felt paper as some call it has deteriorated and just falls off the house. In time from heat and cold exchanges and trapped moisture from your steel sweating the felt will not be an affective vapor barrier and you will end up with moisture in your walls. I recommend that you use a good quality house wrap such as tyvek or any of the others on the market that are comparable.

The only way to eliminate the possibility of the steel sweating is to insulate the walls and ceiling. I realize that is something you don't really want to do but you have to remember that with just steel and a house wrap it is going to be like working in a bean can. It will be hard to keep it cool or to heat it if need be. It will also be very loud when it rains. Just my 2 cents. Good luck with what ever direction you decide to take.

[Reloader]

I personally would not wrap for sheet metal on a garage with no insulation in the walls.  I never do and have not seen an issue.  If I did anything, it would be sheet foam.  The only time we wrap is for vinyl or wood siding on insulated walls. I would wrap only if you plan to insulate.

The easiest way to get some insulation value on a garage or shop is to go with sheet foam, which works better than wrap for moisture as well.


I've seen roofers do various things on sheet metal roofs, some screw directly to wafer board, some use felt, some put foam down, some use stripping, some use wafer bd ,stripping, and foam.  I built my shop and my camp both with 1x4 stripping nailed directly to the rafters and sheet metal screwed directly to the stripping.  I only insulated at the ceiling/joist on both and have never had an issue.  Vent the roof with louvers or ridge cap and you shouldn't have an issue.  I've built many houses and I don't care what you do, it will be hot and cold in the attic space.  The best methods to fight it are foam above the ply, foil coated wafer bd, or foam sprayed on the entire roof system from the underside(rafters and plywood/wfr bd) or a combination of all for the greatest R val.

Have a good one,

Reloader

[Reloader]

Raspy,

I forgot to mention that with ribbed sheet metal, it does breathe.  It breathes through the ribs at the ends.  That's why I stated you only need to wrap if you intend to insulate.  If you insulate with fiberglass, you'll cut the breathing hence needing the wrap.  Insulate with sheet foam and it will still breathe.

If you apply the foam on the exterior, just be cautious when tightening the screws.  Watch the rubber gasket on each screw, it will tell you when you've sealed.  Bury them up and you crush the foam.  Just watch the gasket, when it starts to squish, stop.