Wet conditions make for a nice breeding ground on untreated wood being used outdoors.
Leaving siding untreated.
Cedar has natural antibacterial and anti fungal properties allowing you to leave the wood untreated without worry of excess warping rotting and cracking.
Leaving cedar untreated and exposed to the elements causes its natural honey color to become weathered and gray.
Keeping the natural look on wood siding.
By al rubin pages 24 26 journal of light construction april 1992.
Wood planks and shingles too close to the ground are more likely to swell warp or rot leaving your home with uneven looking contours.
Treated and untreated wood siding can benefit from periodic washing with a pressure washer.
In very dry climates the opposite can also occur.
Pressure washing removes ground in dirt insects and other debris.
In siding as in much else the natural look is in vogue these days with many customers wanting to leave their cedar or redwood siding unpainted and unstained.
Too much direct sun causes the siding to dry out warp and crack.
Most customers however want their houses to retain this natural took with all its honey toned brightness and without the natural graying that untreated wood sidings take on when exposed to sun and weather.
Untreated wood becoming wet can be the first problem.
Most typically when using untreated woods outdoors you are going to run into several potential issues.
This is going to cause the wood to decay rot and grow fungus over time.