Your goal is a neat looking seal over cracks and gaps.
Caulking siding wall good or bad.
Exterior caulking is a lot like interior caulking.
Silicone caulk is expensive but worth the cost due to its flexibility and long life.
In my opinion caulking between the seams in any lapped siding either horizontal or vertical is not good practice but not just because of any potential vapor barrier effect.
Also avoid caulking tongue and groove siding boards together.
Most formulas are mildew resistant and have inhibitors to slow discoloration but all caulk gets ugly over time.
The only big downside is that it s not paintable.
Metal flashing or any metal to wood joint should not be caulked another water exit pathway that should never be sealed.
If you use sashco s acrylic latex caulking sealant you can have any interior or exterior as good as new.
The nails holding up the siding should not be caulked.
The gaps in the siding inside of j channels do not look to bad but hard to tell from the angle of the pictures.
But outdoor caulking deserves some extra attention.
Siding nails should not be caulked another item that needs room to play is siding boards themselves.
You need to have the best caulk for hardie siding to help your walls and wooden surfaces to get rid of open cracks and thin spaces between joints.
Placing caulk over large portions of wood siding prohibits the natural movement of the wooden panels and can cause extensive damage to the exterior of your home.
Generally siding must be cut 1 4 to 3 8 short from any objects.
If you ride the middle or the rough surface siding the caulking will duplicate the bumps sometimes in an exaggerated way.
It needs to move and breathe.
Cleanup can be difficult if you get this caulk on clothing gloves shoes or skin.
It is generally not a good idea to use caulking on wood siding.
I don t like caulking siding j to windows because i think it looks really bad and most guys and manufactures do not recommend it that i have ever seen.
Pure or 100 silicone is the premium caulk for jobs exposed to water.
But here the main problem is people usually don t find the right type of caulk for their works.
Cracks and holes in any surface collect water which causes paint to peel.
Think of a wood home as a living thing.
It will have to withstand all the extremes that nature can dish out.
As homeowners with this kind of siding know wood naturally expands and contracts with fluctuations in temperature and precipitation.
When one of the surfaces you re caulking is rougher than the other try to ride the tip on the smoother surface the brick mold in this case.
And when an outdoor seal fails water gets in and serious trouble follows.
The siding expands and contracts with temperature and humidity.
The best exterior caulk for roofing construction and repairs since it can withstand extreme temperatures and creates a strong insulating and water tight seal.