Repair of an old house: how to replace the lower crown of a log house

Recommendation points

• Types of repair of the lower rims of the house
• Preparing the house to replace the crowns
• Diagram for replacing a section of a log
• Replacement of a log house on a columnar (pile) foundation
• Replacing the crowns of a log house on a strip foundation

Repairing the most vulnerable part of a wooden house – the lower rims – is a very time-consuming work. Usually it requires the involvement of specialized teams with the appropriate equipment, but in some cases it can be done by hand. It all depends on the type of foundation and the extent of damage to the wood of the lower rims of the house.

Types of repair of the lower rims of the house

Consider the types of repairs, as well as the production technology in each of the possible options.

Repair without raising the house:

• with the replacement of the lower crown section;
• complete replacement of the lower rims with fragments of logs;
• replacing the lower crown with brickwork.

Repair with raising the house:

• replacement of the crowns of a house with a pile (columnar) foundation;
• replacement of the crowns of a house with a strip foundation.

The indicated types of repair of the lower rims are arranged in order of increasing production complexity. Replacement without raising the house can be done independently, without the involvement of outside help. Lifting a house requires synchronizing the efforts of at least two people working with jacks to avoid skewing and destroying the house, or sliding it off the foundation..

Preparing the house to replace the crowns

The first stage of replacement is to strengthen the structure of the log house. Even if it is not planned to raise the house with jacks, it will be useful to strengthen the structure. For strengthening, use a wooden bar with a thickness of at least 40 mm, located vertically along the outer and inner surface of the wall.

The lower edge of the timber should be at the level of the crown, which cannot be replaced, the upper edge – at the level of the upper crown of the frame. The screed bars are attached to the wall with nails. At the upper and lower points, they are fixed with a coupler (pins of at least 10 mm) through a through hole drilled in the wall (log). The screeds are located at a distance of 300-400 mm from the edge of the crown section to be replaced, or in all inter-window spaces of the wall.

Diagram for replacing a section of a log

First, the affected area of ​​the wood is determined. It is visually difficult to understand how widespread rot has spread. To accurately determine the damage, either a chisel is used, with which the log is channeled from the side of the visible area of ​​the lesion, or a feather drill in wood, with which holes are drilled using an electric drill.

The condition of the wood is determined by the condition and color of the shavings. Having decided on the section to be replaced, they retreat 200 mm to the sides from its borders, and with the help of a chain petrol or electric saw, a section of the lower crown is cut out. After that, waterproofing is laid on the foundation in two layers..

Replacement of part of the crown. 1. Damaged area. 2. The cut area with a margin of at least 10 cm from the detected damage. 3. Insert

On unaffected areas of the lower rim, cuttings are cut out with a saw for more reliable fixation of the insert element. The lower part of the second crown is treated with an antiseptic. An insert is cut out of a log of the corresponding diameter, its length should be 10–20 mm shorter than the cut area.

The length of the cut should correspond to that of the undamaged areas of the lower rim. After that, the insert is installed (hammered with a sledgehammer) into the opening and the existing cracks are bored with moss or other available material.

Thus, you can gradually replace the entire perimeter of the decayed crown. The replacement starts from the corners from the lower log of the log dressing.

Alternatively, it is possible to replace the damaged area not with wooden inserts, but with brickwork.

Replacement of a log house on a columnar (pile) foundation

This is an easier option, since it does not require the destruction of the foundation. The distance between the piles or foundation posts is usually sufficient to accommodate the jacks. To prevent the deformation of the log house and its sliding off the posts, it is desirable to raise the house synchronously from all four corners of a simple rectangular log house. Only in extreme cases is it possible to lift only one side of the house.

The jacks are put under the upper log of the log dressing. A support is placed under the jack to prevent sinking into the ground (a wooden shield of at least 500×500 mm). The jack rod should not rest directly on the log, but have a metal plate-plate. After lifting with jacks, the lower bandage log is released from the load and can be replaced. Temporary supports made of logs or bricks are installed on it and jacks are lowered.

Simultaneously with the jacks, the upper logs of the frame dressing will also be lowered. They are also replaced and immediately jacked up. After that, the temporary supports are removed from the lower logs of the dressing and the jacks are lowered. The blockhouse falls into place.

Replacing the crowns of a log house on a strip foundation

This work is the most difficult, because it requires: either partial destruction of the foundation to form niches for installing jacks, or the use of a lever system for raising the corners of the house.

The beginning of lifting the log house from the strip foundation using a lever. 1. Bottle type hydraulic jack. 2. Jack pads, steel or wood dies. 3. Stop, steel plate. 4. Lever, bar or steel I-beam. 5. Foundation. 6. Log building. 7. Concrete block as support.

Fixation of the log house when lifting from the strip foundation. 1. Bottle type hydraulic jack. 2. Substrates, steel or wood plates. 3. Stop, steel plate. 4. Lever, bar or steel I-beam. 5. Foundation. 6. Log building. 7. Concrete block as a fulcrum. 8. Wooden wedges

The replacement of the crowns, as in the case of the columnar foundation, begins with the replacement of the lower logs of the ligation of the log house. To do this, niches are cut in the foundation at a distance of 200–300 mm from the corners of the house under the upper dressing logs. After installing the jacks, the replacement procedure is similar to that described above..

When using a lever system, destruction of the foundation is not required. The initial stage is the sampling of half the thickness of the upper log of the frame dressing at 1000–1500 mm from its edge from all four corners of the frame.

After that, a metal channel or rail is laid in the formed niche, and the corner of the house is raised with a jack. As it rises, wooden wedges are hammered between the foundation and the channel (rail) until the lower bandage log is released from the load. It is removed and temporary supports are substituted.

Next, wedges are knocked out between the channel and the foundation and removed. The upper dressing log is released and can be replaced with a new one. After that, the channel or rail is reinstalled and the house is raised using wedges in the same way. Temporary supports are removed and new lower logs are laid for the bandaging of the log house. Lowering the jacks and knocking out the wedges, the log house is lowered onto the lower dressing log. The blockhouse fell into place.

Despite the technology of replacing the lower rims of wooden log cabins, which has been worked out over the centuries, this work still remains very time consuming and requires great physical strength. It is impossible to do it alone. But it’s not only about physical activity, but also about the need to synchronize the rise of the log house at the same time in 2 or 4 points. And with a complex structure of a log house – in an even greater number of points. Nevertheless, replacing only the lower rims is a much less time-consuming process than a complete bulkhead of the entire log house..