My deck needs to be restained, but before I do that there are some
rotten boards that have to be replaced. These boards are rotted in a
corner at the end where they meet a step up. That corner is shielded
from sunlight and wind so leaves gather there and stay wet, hence the
rotting.

My deck floor is made out of 2x4s rather than deck boards. I'd prefer
to just cut back the rotten boards to the nearest joist(?) and put in a
new piece. If I go that route how far back should I go to ensure
stability? The nearest joist seems to be a foot away. Would it be
better to go back two full joists?

I assume treated lumber is necessary so the question arises whether
this will accept stain. How do I prepare it for stain and hopefully
make it match the rest of floor?

| My deck floor is made out of 2x4s rather than deck boards. I'd prefer
| to just cut back the rotten boards to the nearest joist(?) and put in a
| new piece. If I go that route how far back should I go to ensure
| stability? The nearest joist seems to be a foot away. Would it be
| better to go back two full joists?
|

You can just replace one section, provided that
there's enough joist under it for support, but it
won't look very good if you do several like that.
If there are a number of them next to each other
it'd be best to stagger the lengths of the
replacement pieces.

| I assume treated lumber is necessary so the question arises whether
| this will accept stain. How do I prepare it for stain and hopefully
| make it match the rest of floor?

You can also use fir. It won't resist water for as
long, but it has a nicer grain. PT 2x4 can be pretty
rough. Even the PT 4/4 x 6 doesn't make for a very
elegant look. 2x4 is not meant to be used for flooring,
so it's usually much rougher, often with big knots.

Fir can be stained immediately. PT should dry, at
least until summer. If you use a solid stain you don't
need any particular preparation other than maybe
washing with TSP solution. If you have a transparent
"wood color" stain you won't have much choice about
PT green showing through.

I guess you could might also use cedar, but 2x4
cedar is not available where I am.

"badgolferman" wrote:
My deck needs to be restained, but before I do that there are some
rotten boards that have to be replaced. These boards are rotted in a
corner at the end where they meet a step up. That corner is shielded
from sunlight and wind so leaves gather there and stay wet, hence the
rotting.

My deck floor is made out of 2x4s rather than deck boards. I'd prefer
to just cut back the rotten boards to the nearest joist(?) and put in a
new piece. If I go that route how far back should I go to ensure
stability? The nearest joist seems to be a foot away. Would it be
better to go back two full joists?

I assume treated lumber is necessary so the question arises whether
this will accept stain. How do I prepare it for stain and hopefully
make it match the rest of floor?

If I am picturing the deck correctly, it sounds like the 2x4's butt up to
step-up with the end grain near the step up. The end grain has absorbed
moisture and the boards are rotting.

If that's correct, would it be possible for you to cut _all_ of the 2x4s
back to the next joist, add some blocking in the open space and run boards
perpendicular to the 2x4's/parallel to the step up. This would eliminate
the exposed end grain in the area that collects leaves and moisture. Should
the new wood begin to rot, it would just be a matter of replacing one or
two long boards instead of having to weave in a bunch of 2x4's to make it
look right.

You would be incorporating a design element into the repair.

"badgolferman" wrote in message
...

My deck needs to be restained, but before I do that there are some
rotten boards that have to be replaced. . . .
My deck floor is made out of 2x4s rather than deck boards. I'd prefer
to just cut back the rotten boards to the nearest joist(?) and put in a
new piece. If I go that route how far back should I go to ensure
stability? The nearest joist seems to be a foot away. Would it be
better to go back two full joists?

Only after the deck boards are removed can you assess the
joists for rot and stability. These interact: i.e. using joist hangers,
corner braces etc. will reduce movement and delay further rot.

The rule of thumb is to insert metal (either a joist hanger or a
shim of flashing) wherever wood rests on wood. The whole
structure should promote rapid drainage and drying, e.g. there
should normally be an air space (1/8 to 1/4") wherever two board
ends meet.

I assume treated lumber is necessary so the question arises whether
this will accept stain. How do I prepare it for stain and hopefully
make it match the rest of floor?

Non PTL lumber should be treated with some sort of preservative
before use, on all 6 sides i.e. including cut ends. If this is also a
stain, so be it: but matching deck board stain to older deck boards
will require experimentation on a larger area than just the new boards
after weathering for a month or more.

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)