Housewrap

[Dahammer]

I'm currently in the planning stage of building a new 2000 sq ft brick veneer home in north mississippi. I have a question about housewraps. Actually, I have alot of questions, but you can only eat an elephant one bite at a time, so. Around here it seems there is no standard between builders regarding this issue. Some new homes going up are wrapped with Tyvek, some with other housewraps, some not at all. I saw one the other day that had OSB all the way around and no wrap at all. They were laying the brick against the bare OSB walls. That didn't seem very smart to me, since if it gets wet, it's history. A freind of mine built a house a few years ago and he said his builder used OSB and then installed a foam board on top of that and taped the seems. He said the styrofoam board had an aluminum backing on both sides as well. Then you ocassionally see builders using the pink foam board and then wrapping it with housewrap as well. All this has me confused as to what to do and what not to do.

What I want is a structurally sound, energy efficent home that I can enjoy for many many years to come. I don't give a rats behind for all the fancy trim work, 6 figure cabinetry (yeah, had a guy tell me he wired a home awhile back where the lady actually spent 150k on cabinets alone!!!), and etc. But things that I have a 1 shot chance at getting right, I want done right. So what's the best thing to use for my climate in regards to Tyvek and/or foam board? The winters are generally mild here, although it does dip into the 20s frequently, hovers in the 30s for several weeks, and gets very hot and humid in the summer. The exterior walls will most likely be 2x4. BTW, I'm out in the county and there is no code whatsoever.

[concretemasonry]

Whether you have a code or not makes no difference since it is only a minimum and most people are not bottom feeders unless they are low-ball "contractors".

You need a moisture barrier behind the brick or any facing material. Tyvek is a proven material, although there are some newer spray on materials that cost more and do a better job. It must also breathe. Any board not taped and sealed does not qualify as a moisture barrier. Some may prohibit breathing.

A good exterior wall consists of a rain, or surface water barrier and a moisture barrier behind. In terms of value, appearance, structure, thermal home performance and life, brick is at the top, with vinyl and othe materials rated below.

Frankly, the biggest problem with putting a weather tight exterior on a house is the "wood butcher" that tries to install windows and doors. From what I see in problems and inspections and mold investigation, over 50% of the windows are not installed correctly (some figures are up to 70%). Make sure the windows are installed EXACTLY according to the manufacturers instructions or have a Certified Window Installer do the work. A poor installation job can destroy an otherwise outstanding home in the long run. As a test, ask your installer about "pan flashing". If he does not know what it is or does forget about him.

All siding material (brick, vinyl, etc.) need a way to maintain the same air pressure behind the rain barrier.

With brick veneer, make sure you have "weeps" installed about 24" on center horizontally in the first course of the brick. Also, make sure you have vents installed at the upper part of the wall. The vents may be hidden above the soffit. - You will see holes in the bottom of each piece of vinyl siding that do the same thing. With brick veneer, you should also have flashing under the wrap at the bottom of the veneer that directs any moisture outward through the weeps.

Good luck!!

Dick

[Dahammer]

Thanks for the suggestions. About the weep holes in the brick. The plan is to place the house on a supported slab foundation (raised slab). Due to the soil conditions at the site, I'm going to have to dig the perimeter footings about 4' deep. We then plan to backfill the trenches with 2' of crushed 1 1/2" limestone, on top of which the footings will be poured. From there we plan to use concrete block to raise the slab to the desired elevation, which will be approximately 16" above grade. So in all likely hood, the first row of brick will be 2' or so below grade. I don't anticipate that causing a problem with the weep holes though since they can still weep, albiet a bit slower since they'll be under ground.