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Log Repair
Repairing Rot Damage in Your Log Home
We discussed in the previous section the minor repairs you can make to the checks, cracks, knots and the odd soft spot on the log. But what do you do if you have major log rot? Large sections of a log are rotted, or a whole group of logs are bad? Serious business! Log replacement would be ideal, and we encourage it if you can manage it or afford it. But what if you can't?

So, we're back to the Clear Penetrating Epoxy Sealer™ (CPES). We'll say again that to our knowledge there is no other product on the market but CPES that can even come close to restoring bad wood. It is the highest grade epoxy resin available and it's mixed with a powerful multi-component solvent/activator solution that can penetrate deeply into wood. Its application is the first and most important step you can make toward restoring rotten logs. After the CPES a lot of things will work - but only after the CPES.

CPES application to bad logs is not a quick process. The bad wood must be reasonably dry. If it's not, then you have to dry it. Large kerosene blowers (80,000 btu) are available from rental stores at a reasonable price, and they can dry a lot of wood quickly. Compressed air pumped through wood will also dry it quickly. CPES has to be applied to the interior of the log as thoroughly as possible. It has to be allowed to cure and the solvent mixture to evaporate away. It takes time. Depending on your situation, there are two ways to go about this, and we outline them here:

Method 1:
Drill and Fill
Drill and fill is for when you know that the rotten interior is intact, reasonably dry and you just want to saturate the bad wood with CPES to stop the rot and restore solidity to the wood.

(1a) Drill 1/2" or larger holes about every 6 inches as high up on the rotted section of the log as possible. Drill alternating holes at shallow and steep angles, 30°, 45°, 60°. Drill deeply and inspect the wood coming out. Is it reasonably dry? If not, provide a loose plastic cover and allow air to circulate through to dry wood. This may take several weeks.

drill illustration

(1b) When wood is reasonably dry, inject all the CPES the log will conveniently accept. Large cooking basters or garden sprayers are ideal for applying large quantities. Or you can use a funnel and hose. Allow 3-4 weeks for solvents to evaporate and the epoxy to cure. Again, cover with a tarp if wet weather is a factor. If the log is hollow, the tip of a garden sprayer can be bent to insure total CPES coverage of the log interior.

fill illustration

(1c) Fill cavities under holes with any "thick" fluid you choose that will set up hard. The best is our Layup & Laminating™ Resin/sawdust mixture that will bond with the CPES. Do not use soft putties or fillers.

funnel method

(1d) Apply CPES to bungs and drive them tightly into the holes, or fill holes with a putty mix of Layup & Laminating Resin and sawdust. Grind or chisel bungs smooth and coat exterior of bungs/logs with CPES. Apply whatever finish coating you choose, as long as it is a pigmented stain, or a clear coating with a UV inhibitor.

bung illustration

Method 2:
Rip, Dry and Treat
Rip, dry and treat is for when the wood is wet and badly decayed, or there is a large hollow vacancy that must be filled. You remove the exterior face of the log, treat the part of the log exposed by removing the face with CPES, fill the voids and replace the log face.

(2a) Use Sawzall or similar tool to cut away the exterior face of the log. Save log face for later replacement. Scoop away all loose, wet, decayed wood. Allow area to dry. If in a hurry, blow-dry with a rented kerosene blow-dryer. We've used the 80,000 btu units propped on a stand.

sawzall illustration

(2b) Apply CPES to interior of log and to facing that was cutaway. Use a large, disposable bristle brush and keep applying until the wood will accept no more. Allow 4-5 days for solvents to evaporate and the epoxy to cure. Additional CPES access holes can be drilled in the interior if you think it is necessary.

CPES application illustration

(2c) Fill hole with pieces of wood that have had CPES applied for rot protection. Use our Layup & Laminating™ Resin/sawdust mixture to fill in around them and close gaps. Do not use soft putties or fillers.

Fill-It illustration

(2d) Apply Layup & Laminating™ Resin; to cut log surface and replacement piece. Put in position and allow epoxy to cure (1-2 days). Smooth log exterior surface and coat with CPES. Apply whatever finish coating you choose, as long as it contains a UV inhibitor.

re-glue log face illustration

We should mention that any type and size wood can be used to fill vacant spaces in logs, but they should all be bonded in place with our Layup & Laminating Resin or a mixture made from our Layup & Laminating Resin and sawdust. Any large pieces used for filling should be treated with CPES before being bonded in place. Smaller pieces, such as wood chips that will be encapsulated with the resin, can just be mixed with the resin and applied. Dissimilar materials such as concrete should be avoided because they condense moisture, and moisture plus wood promotes fungal growth.

Here is a sample log that has been repaired. Before the cracks were filled, they were saturated with the CPES. CPES flows where the water flows and hardens any soft wood it encounters. It also virtually eliminates the possibility of future rot or deterioration inside the log. This is a particularly good use of CPES on a log home, particularly on all upward-facing cracks.

The photo (below left) shows a mix of the Fill-It Epoxy Filler being pumped into a crack with one of our re-usable caulking tubes. The Layup & Laminating Resin/sawdust mix can be pumped into a crack in the same way. The filled areas were sanded and then stained. The key to getting the Fill-It a near color is to put down a sample of the stain and then mix our brown Epoxy Coloring Agent in with the Fill-It until a close color is matched.

Click on images to see enlarged photos.

Fill-it pumped into crack
Color matched Fill-it
Log Home before filling Log Home after filling
The photos above show this same filling process on a log home, before and after. Note that the affected logs have had holes drilled at the top edge for the injection of CPES™ into the log interior.

The photos below show a repair of corner log rot using Rot Doctor’s CPES and Layup & Laminating Epoxy Resin thickened with sawdust. This is a good example of using new wood to give finished surfaces and to fill vacant space.

Click on photo to see larger version.
Picture 1
Pic 1: Soft wood is removed.
  Picture 2
Pic 2: Affected areas and new wood are saturated with CPES.
Picture 3
Pic 3: Vacant areas are filled with a combination of Layup and Laminating Epoxy Resin mixed with sawdust, and new wood.
  Picture 4
Pic 4: The repair is complete.

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log house image Log Repair: A Case Study
This is a picture of a beautiful log home in the Northwest. The picture to the right shows the front of the home, which faces the Northeast, away from incoming weather. Wide roof overhangs have kept much of the water off the entry area and the logs look presentable. To the sides of the entryway and on the broad face walls the overhangs are short, and the logs are discolored from running water. There was very little if any protective coating. Even so, because they get less rainwater, sun and air circulation, there was very little serious damage to the logs.

Porch View
Window sill

The back of the home has a broad concrete deck which drops off into a long valley and a lovely view of the Pacific Ocean and distant shoreline. We show you the deck and the view, which is to the Southwest.

Unfortunately, it is from the Southwest that the strong winter storms arrive, with high winds and lots of rain. The protection of the roof overhangs helped near the top, but at the bottom there was extensive rot in almost all the logs. The sill logs directly under the windows, which caught the water running off the glass, were so soft they could be easily pushed in with your foot. They were virtually hollow inside. We show above a picture of one sill log. You can see cracks, splits and knots where the water got inside.

log home porch
closeup of repairs
closeup of repairs

The owner of this home discovered all these problems late in the season, just before the winter storms were due to arrive. The upper logs were less damaged and were okay to treat by method 1, drill and fill. The lower logs (especially under the windows) probably should've been treated with method 2, rip, dry and treat. There simply was no time to cut away the faces of the logs and get inside. His solution was to get as much CPES into these really bad logs as possible. His belief was that large amounts of the CPES would harden the wood it reached, discourage or encapsulate the rot fungi, and certainly create an internal environment that the termites found disagreeable. It would not solve the problems, but would at least help retard further damage.

Staging was set up and the process begun. You can see in the next picture that holes have been drilled and CPES injected into the two logs between the windows. Closer detail shows holes that have been bunged closed after the CPES injection. We do not recommend this, but this owner had no choice. He was smelling solvent fumes for a long time. It is better, if possible, to leave the holes open for as long as possible to give the solvents a way to migrate out of the wood before plugging the holes.

A word of advice here . . .
For those of you undertaking such a project, the holes should be much larger, 3/4" to 1 inch. This allows a greater air volume to circulate, which is what it takes to allow the carrier solvent fumes to evaporate away. Even so, a heavily saturated log may take 3-4 weeks before the solvent fumes are gone and the holes closed. In addition, the holes should be drilled as close to the top of the log as possible, and at varying angles into the log. One half to three-quarter log diameter penetration is recommended. This will ensure that the CPES reaches all the rotted areas. If rain and bad weather are an issue, we recommend hanging large tarps to keep the area reasonably dry.

The first closeup picture to the left shows bungs in place and some bungs trimmed off. The home owner has elected to use our Fill-It™ Epoxy Filler to seat the bungs and ensure that no water can enter. You can also see that a mixture of our Layup & Laminating™ Resin and sawdust has been smeared over the log surface to fill the small cracks. This forms a very hard fill that adheres strongly to the wood. Every crack on every log should be filled with this mixture after first being treated with CPES.

The next picture shows an area that has been CPES injected, filled, and then ground down with a disc sander for final finish coating.

Log overhangs (right) too were treated with CPES and filled with the Layup & Laminating™ Resin/sawdust mixture. We also recommended that the log ends be thoroughly saturated with CPES, applying as much as the wood will absorb. CPES will migrate in a long way with end-grain application.

log overhangs

The moral to this story is never let the situation become this bad. Constant attention to the home exterior and the use of appropriate products will prevent drastic measures later on. In our opinion every log home owner should have on hand some CPES, some Layup & Laminating™ Resin and some sawdust. Other (and cheaper) epoxy resins can be used, but keep in mind that they are not as strong or as flexible as our L&L Resin. Both the CPES and the Layup & Laminating™ Resin have an indefinite shelf life if unmixed, kept in closed containers and kept above freezing.

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