I am building a new house and ,plan on using board and batten for siding .I have a lot of pine (FREE) but I don't think it will hold up if not treated with something . I have priced cypress wood from a mill south of me ,but I can't fine /buy cypress logs around my area. The question I pose is to buy cypress are treat the pine with Thomson water seal are a equivalent chemical.
Use the pine, lots of houses and barns have pine siding and it holds up fine. I have had customers mix pine and cypress and after it weathers a bit you could not tell the difference.
Don't be fooled into thinking that the Cypress will last any longer than the SYP will. Today's Cypress is sawn from ~24" logs (and smaller) and have very little rot resistant heartwood. I have a friend that sided his new cabin with Cypress board & batten and within 10 years he was having to replace rotten siding.
Whatever you do, do not allow any roof runoff, etc. to splash up onto the siding. I also like to saw a ~30° bevel on the bottom edge forming a drip surface and preventing water from continually wetting the bottom edge of the siding.
I would treat the siding as you suggested and follow up with a sprayer as needed to prevent water from soaking in. There is nothing necessarily wrong with it getting wet, but there is with it not being allowed to completely dry.
Magicman's advice is sound. While my house is western cedar the same principles have kept mine in good condition for 29 years. Plenty of air movement, no shrubbery or trees against the house, gutters and down spouts that ensure the siding stays as dry as possible and enough distance from the ground to the siding (foundation height above grade) to minimize splashing.
Plus don't be afraid to wash your siding on occasion, dust and pollen accumulations turn into algae and mildew. The north side of my house is prone to the algae and mildew. I use a long handled brush and siding wash then rinsed with the pressure washer (held back enough to wash without gouging). All this is followed by sprayable clear siding preservative ( I've used several different products over the years).
I used a stain made by flood. It has held up well for years.
I use copper napthenate the copper prevents rot goes on a nasty green but turns a golden brown in the sun could take a month or two, the oils help keep the water out and helps keep it from cupping or checking as bad
I sided a mill building 25 yrs. ago with pine boards and 4" cypress batts. I wanted to see how long the pine would hold up compared to the cypress.I could see that getting cypress was going to become more difficult in the future (and the future is now!) and I wanted to compare the pine and have a demo building to show customers. The pine is natural seeded, no plantation wood. Where dirt, sawdust, and other debris has accumulated at the bottom of the wall the pine has rotted up about 6-8" , the cypress about 3-4. Above this zone the pine is showing some signs of heavy weathering, while the cypress , not so much. My "WAG" is the pine is good for another 15 years or more, the cypress much longer than that. Nothing has ever been done to the boards, and there is no protective overhang. The building is away from any shade, and is fully exposed to our hot, humid weather. YMMV, but that's my results.
There was a great article several years back about treating lumber in two steps. Step one is to treat with a boric acid based solution (discourages wood eating pests). Step 2 was to treat with Copper Napthanate (CuNap) for rot prevention.
So far it's worked well for me here on the farm.
thanks to all for there input ,after reading all the post it seems pine is the winner .magic man would you put the 30 degree bevel with the long edge out?
Yes so that water will drip off of this sharp edge and not wick under the entire board. I bevel both the board and the batten.
I sided my mill with cypress board and batten and wanted to preserve the bright look as long as possible. So I use Thompson with the UV protection, it has been almost three years and still looking very good. Will probably treat again next year. As we put up the board we set the end of the board in a small tub to soak, so board up and a board into the tub. Next we rolled the siding before the battens were put up, easier with a flat wall. To treat the battens I got a piece of 6" pvc and two end caps. Cut the pipe to form a trough and dunked the battens to cover all sides. When removing the battens a shop towel acted as a brush to remove excess. Lot of work but I've never been good at easy, even when easy is better. Could be I'm a little slow upstairs.
I've had good luck with used transmission fluid. It gives a better color than used motor oil, unless you want black. And it's cheap.
Im thinking that maybe there is more of a problem in the hot humid south.
there are many barns in cny sided with Hemlock, unfinished for anywhere from 50 to 100 yrs and will just show a little deterioration in the extreme lower parts.
If finished with stain or paint they are in very good shape.
M.M. got good advice. Whats important on siding is overhang of the roof, siding high off the ground and no tanks, bushes, etc. to cause splash or stop air flow. A bevel lower cut is better than square, actually round is more rot resistant like stair treads.
Took down a garage two years ago that had 40 year old untreated hemlock board and batten. Other than being grayed on the outside, it was unaffected by the weather.