Tree cavity

[KevinS]

Yesterday I was working on some old trees that had some cavities and I got wondering.
We used to paint wounds, fill cavities with cement, brick, etc. Which is now frowned upon and I've seen cavities sealed with tar, foam etc which is still questionable but clearly better for your saw but could still hold moisture and rot further.
If you do nothing cavities will fill with rain, snow, ice and freeze thaw, wet dry and rot can build from there.

My wonder yesterday was if you cleaned up the cavity say with an air spade on a dry day so you have a clean dry cavity then what would happen if you fill the cavity 3/4 with kitty litter or some dry spill absorbent then capped it off with foam or tar?

That would leave a clean dry cavity that could not fill with ice, etc and would not hold moisture.

Does this idea make any sense or am I over looking some obviously huge detail that screams dumb idea?

 

[GregManning]

Pure guess:
Moisture from the tree would quickly transport into the kitty litter, and you would have a nicely sealed mud pie. (clay pie)

 

[KTSmith]

I'm probably just repeating GregManning here, but the general problem with using adsorbents or dessicants is that once the material does get wet, it will hold on to the moisture, particularly if capped.

 

[KevinS]

Pure guess:
Moisture from the tree would quickly transport into the kitty litter, and you would have a nicely sealed mud pie. (clay pie)

That was the first downside we thought of as well

 

[DSMc]

Depending on the extent of damage occurring during the freeze thaw cycle and if water deflection methods will not work, you might want to consider the out of date and frowned upon idea of adding a drain.

 

[Tree_Frog]

This video at about 15:37 leaves a good argument for using hot tar. Personally, I do not have enough experience with tar to make an educated decision.