Does chemical spraying dry rot work?

[TwoTicks]

We had dry rot on floor joists and stone wall in one room of a 200 yr old house, which was sprayed. Now less than three years later it's back (there was a small hole in the windowsill that let in moisture). And this time it's on the lintel too that's being replaced. The stone was bored last time, but only a few holes and straight into the stone and not into the joints between stones.

Last time only a few holes were bored into the external stone wall of the affected room but the company we plan to use this time say this was wrong and the idea is to bore "a lot" of holes into the joints of the stone so the chemical can percolate down.

Have you ever seen stone or timber treated or sprayed for dry rot and come back in the same place? We are not spraying for insurance purposes and we are not getting a guarantee because we are not going a metre down into the room below (cornicing etc). Is spraying worthwhile? How many holes should you bore?

 

[gregers]

well when i used to do it we used to drill every 12-15 inches in a diamond pattern at approx 45 degrees and flood the holes,but im am now lead to belive that the new method is containment where they drill a series of holes to stop the rot from travelling further.

i still use the old method when i encounter dry rot.

when you had it treated before did they issue a guarantee if so then claim on it thats what you paid good money for.

 

[TwoTicks]

No, I don't unfortunately. And thank you!