PinkFloydEffect
ArboristSite Guru
The foam will cause moisture to get trapped inside of the cavity, the bacteria that causes rot will thrive in a sealed environment, more likely to progress at a faster rate then if left open to air.
I agree I don't see any slime flux either. The crack should be looked at by a qualified arborist though. It looks to have rot in the space, it should be probed to find out how much is rotten.
Don't do any major pruning unless they are hazardous limbs- your mature tree shouldn't need much servicing any more, dead wood, broken limbs, perhaps some selective branches that are growing too close to your house- but other than that don't touch it.
Ciao
Thanks! The hole with the water coming out dosent seem to dead pretty stiff wood right to the crack crevice.
As far as pruning goes... eh. It's not too close to any house however I do think it needs some structural work. Its oddly shaped and has a lot of snapped tips everywhere with no close nodes to them so the snapped tips need to be cut back and there's some dead wood that should be removed (also so I can see how far it travels from that dead spot up high) I was also talking with few people about going a bonsai style with the canopy and bringing it back so there is less weight to support and it will throw out new shooters to fill in the canopy more. However all this needs to be taken into careful consideration as you state about it being fully if not over mature. I think the thinned canopy can also be from the roof flares being buried so deeply and a tree service from the Merrimack Valley should be looking at them come spring time.
Keep your eyes out I'm posting a video tonight (link will be on here) of the trees update 4 month's after the root flare unburial and the buds are looking more vigorous already!