Rotten Wood problem

[Rezi]

In my oldish house there are a couple of internal doors that have obvious rot at the bottom of the frames. The rot is caused by a lack of damp proof course on one particular internal wall which needs a dealing with but I don't have time right now.

Before starting, my plan was to cut off the bottom section of the frames on all sides and replace it with new wood. However, now that I've done that, I can see that the internal post is also badly affected. I'm not concerned with the integrity of the whole frame as this is only a localised problem so, my intention is to clean it up and carry on with the plan and fix it cosmetically for the time being.

The issue I see is that I am left with a void which will give me issues with fixing the new wood. I was trying to think of a material to use to fill that void and, other than expanding foam, I'm out of ideas.
Any suggestions would be welcome.

 

[Doug]

Why not expanding foam seems an ideal product for this situation?

You can get expanding foam tape https://www.affixit.co.uk/expanding-foa ... ative.html if you’re dead set against use expanding foam

 

[RogerS]

I think Steve's problem is with not having anything to screw into. I could be wrong.

Steve...any chance of some photos ?

 

[AndyT]

If I have understood you properly, I would find a chunk of any old wood, cut it roughly to size and fix it in the void. Use any fixing that works - nails, wedges, screws, construction adhesive - and add extra bits of wood if your first bit wasn't big enough.

 

[Rezi]

I'm not dead set against expanding foam at all, I just meant that that was the only thing I could think of and wondered if anyone had any other suggestions.

That's basically it Roger. I can find long enough screws to get through to the dry wood underneath but now that there is a void how do I hold it in position so that I can make the repair as invisible as possible. A bunch of spacers and some trial and error would work but, if expanding foam is the best solution, then I could get the new bits in position and fill the void behind though a small access hole.

 

[RogerS]

No, expanding foam is too soft for the task in hand.

I would scrape away as much of the rotten wood as possible to give yourself a firm base. It doesn;t need to be level either. Use one of the wood hardening stuff from Ronseal (other makes are avilable). Pack out with any old scrap and screw them onto the inner piece of wood. Doesn't matter if you need to use several layers and screw as you go. The goal is to build up a sufficiently secure backing onto that inner piece on which you can then screw your door liner.

Then when it's all done, use foam to fill in any gaps prior to making good with any sort of decorators filler.