ConServ Epoxy LLC



Offering various FLEXIBLE and STRUCTURAL epoxies for your restoration needs

Process for Restoration of House and Barn Sills

House sills, barn sills etc. can often be restored with wood preservative and epoxy.  The sills usually rot from the bottom outside area and the decay fungus works its way up and into the sill.  If there was a membrane such as EPDM below the sill, the rising damp would have condensed underneath and went back into the foundation hence minimizing the chances for the fungus to take hold and breakdown the wood. 

Replacement of sills is not always the best option.  Once the sills have been exposed from the outside and preferably 1'-2' above the sills so the stud and post bottoms are in view, a better analysis can be done. Criteria for restoring them could include 
1. Visibility of the historic fabric from the inside 
2. Stud and post connections on top of the sills 
3. Condition of the foundation below 
4. Whether there are intersecting joist and girders plus the condition of these perpendicular members if they exist 
5. The extent of decay and settling in the sill itself 
6. Whether the specifications include lifting the wall above to correct the elevation. 
The question of cost to replace verses restore will probably be answered after professionally analyzing these six criteria.

A technique I have found to be successful when the sill is to be restored is as follows:
1. prepare the wood by removing most of the decay
2. cap or repoint the foundation top as needed
3. cut and fit EPDM membrane over the exposed foundation and wedged it under the sill when possible
4. if large voids exist, cut dry wood filler pieces to very loosely fill the voids, number and mark their locations
5. apply borate preservative to all fillers and framing that has had decay and is prepared for epoxy, this includes stud and post bottoms, this step is good insurance to kill fungus that probably still exists in the wood
6. verify that the wood is below 20% moisture content, then apply epoxy consolidant #100 on all the surfaces of wood that will be getting filled
7. apply epoxy patch #200 into the existing sills and on top of the EPDM, fill the large voids approx. 50%-70% then press the consolidated fillers into place and allow the patch to ooze out and around encapsulating the wood fillers
8. the epoxy patch should be mixed thick enough to hold its shape without slumping so you can fill all voids in plane with the surrounding wooden fabric, this includes stud bottoms if they need to be filled
9. if there are large voids under posts that carry heavy loads, you could use the #600 epoxy thickened with #200-1D (fumed silica) prior to, after or in conjunction with the work above.  The #600 can intersect cured or uncured #100 or #200 epoxy.
10. once the epoxy patch #200 is cured it can be tooled as needed to maintain the plane and a second coat applied as needed
11. treat the #200 patch as if it were wood and proceed with the restoration process, using fasteners through the #200 as you wish
-Paul Marlowe
ConServ Epoxy LLC Owner

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