How to Jack and Repair Antique Structures

How to Jack and Repair Antique Structures

No.1 The process to lift and repair this building is explained in this short pictorial primer. The damaged arias are located and exposed and the size and extent of damage is determined. If you are not sure, take a hammer and pound on the sill. It you get a high pitch dead blow sound the sill is solid. If the tone is low with a bass sound you most likely have a sill to replace.

No.2 Measurements are taken off the building and a field drawing is made. The drawing allows the measurements to be transferred to the horizontal lifting plates. All lag holes are then laid out, checked for accuracy and drilled in preparation to install the plates to the second story spanners and first floor wall studs.

No.3 The jacking plates are lifted by two men carring them up a ladder and setting them in place temporarely. They are lifted to the final location and timber locked to the wall.

No.4 when the plates have been alighaned properly the final 1/4inch pilot holes are drilled and the plates are lagged to the wall.

No.5 At this point the ground pads are located and the angles set. The angle of the pads is crital and may have to be set a few times until they are stable. The blocks and jacks are installed next and the post are measured and measured for length and cut. The posts are installed and light pressure is taken up in them.

No.6 Oak 4x4s are installed under the floor parallel to the foundation.Posts and jacks are installed vertically to support the floor are its proper height and to allow the house to be used with out interruption.

No.7 With the jacks in place and under load the weight can be taken off the foundation in order to remove the damaged sills. The floor frame work is measured for length and depth and all detentions are recorded on a field drawing. From there the measurements are transferred to the new sill timber and laid out accurately. The mortise and tenons are cut as well as joist housings as necessary in the sills.  This work is preformed with skill saws and, Fostner bits and old fashioned chiseling.  This phase of the project takes time.

No.8 The sill is moved into position to the inside of the jacking posts and set on to blocking at the same height as the foundation. The first fit is made to see if all the dimensions match each other. It is inevitable given the condition of multiple variables that all inside and outside dimensions will be perfect.  The sill usually has to be backed out onto the blocking and turned up if necessary and have the adjustments made. Once the adjustment has been made the sill is turned and reset on the foundation. This is typical in every insulation

No.9 There are reoccurring situations that require removing a piece of the leading edge of a joist housing to stop it from binding on the joist or girder end. The condition is more prevalent on the beginning joist than at the end because the angle is less as the sill goes into place. Occasionally, a housing will be too shallow or a tenon too long by a bit. This is field work and there are a lot of adjustments to be made to get old buildings to accept new sills. Kind of like new shoes.  It’s good to check and check again. These buildings were made by hand. Every piece of wood was hand shaped and custom fit. We have to do the same process only in reverse.

No.10 When the work is completed the sill should be properly sealed with a good oil bias product, lagged together and all post, wall studs, girders and floor joist should be a good fit and soundly connectee to the building. Remember that you only get one chance to do it right in 200 years.

George Yonnone

Training Sessions- How to Lift & Repair Antique Buildings

My name is George Yonnone, I have been repairing and replacing structural components to antique buildings since 1970.  I love what I do and I love traveling, so it works out well.  I am asking if you would be kind enough refer my company to clients seeking a professional repair/restoration company to make repairs to their homes or barns. This is assuming that your company does not perform this service and there are not qualified professionals in your region.  I specialize in the repair, and restoration of 18 and 19thC Homes, Barns and Log Cabins as well as large wooden column restoration.  A majority of my work consists of jacking buildings up, pulling them back together and squaring the frame.  Needless to say I spend a lot of time replacing poor repair work performed by well meaning although inexperienced carpenters.  I work nationally serving clients that are unable to find qualified companies in there aria who are willing to tackle large building repair.  All repair work is guaranteed unconditionally.  I ask that any referrals mention your name so that I may have the opportunity to thank you.  Sincerely George

I will be offering seminars and training sessions in the fine art of lifting and repairing antique buildings. The subject to be taught will be Structural Repair and will focus on grade sill replacement.  Based on current trends in the building trades it appears that the term structural repair has been eliminated in favor of building to existing conditions.  Although this work can be intimidating, it is always broken down to a series of smaller repairs and achievable goales.  In this course I will discuss how to recognize potential damage, how existing sight conditions and water contribute to the damage.  I will also cover the need to right the building. Including 1 Preparation and installation of the jacking system, 2Measuring and preparing the jacking plates,3 installing the plates,4 Lifting and leveling the building, 5 removing the original damaged grad sill, 6 documentation of the building and housing locations, 6 building and replacing the new sill and 7 resetting the building. The procedures and training will be enhanced with inside tricks and tips acquired over the past 43 years of discovery.

A date and location will be announced along with fees.  If you have a client who would like to share their Antique building as a teaching model, Please contact me. Attendance will be limited to 10 ten qualified participants (Licensed and Insured Tradesmen With tools).  10 Apprentices with their own tools and Liability Insurance or insured by a contractor in the program.

All other interested parties can ask questions and observe from behind a barrier.

This is not as yet an accredited program, however, fore those dedicated to the preservation of antiquity, this is the ground floor knowledge you need for the 21st century. It’s time to learn how to do it right  Tradesmen and apprentices interested in attending a structural repair course in the future should send an Email to George@gyrestorations  Participation will be subject to the location of the project. To Be Announced, the course is estimated to run 10 days.  Cost to be announced. Regional sited will be chosen to teach the methods described above and the applied physics related to safe structural repair.

This course will also be offered to Restoration companies that perform structural repair either full time or selectively and wishing to have seminars preformed at your clients site or project to improve the efficiency and competence of your staff in structural repair methods as well as the long term quality of your repairs and the long term health of the building.

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Documenting Historic Restorations

The word Restoration is painted with a wide brush and like the strands of that brush it represents many different crafts and skills.  Some people train for years in college, some apprentice with tradesman or artist and others realize a natural gift … [Continue reading]


By George Yonnone  On  October/21/2002 I received a call from Jim Rayner of Lowell MA. He had been directed to me by Preservation Consultant John Leeke of Portland ME.  Jim asked if I would come and look at a column restoration project in Lowell … [Continue reading]