December 1999

by Gordon Bock – photographs by Jon Crispin

Reprinted with Permission

Sills may be the lowliest parts of a wood frame house but, like the keel of a boat, they form the base that supports all other structural members. When old house sills succumb to rot and insect damage, [...]]]>

Old House Journal December 1999 by Gordon Bock – photographs by Jon Crispin Reprinted with Permission Sills may be the lowliest parts of a wood frame house but, like the keel of a boat, they form the base that supports all other structural members. When old house sills succumb to rot and insect damage, it takes technique and experience to replace them. GEORGE YONNONE RESTORATIONS has specialized in this heavy repair work for over 25 years. Since George welcomes any opportunity to share his knowledge, we visited him on the job at an 17905 timber frame house to see the process he uses to successfully jack and repair all kinds of buildings. Like the best restoration projects, sill repairs start with assessing the present conditions, Sills tend to decay from the outside in, and while they may look good from the basement side, 1/3 to 2/3 of the wood can be gone under the exterior siding. Along with probing with an awl for deteriorated wood fiber. George relies on “sounding” to assess sill integrity. Tapping the wood with a hammer from the basement side produces a telltale tone. A good sill rings with a high pitch; if there’s a little rot on the outside, the pitch is lower. If the sill is really suspect, and the owner is comfortable with a little exploratory surgery, George pops some siding off to survey the sills from the outside. When inspection reveals a bad sill, the first repair step is to remove siding at the second-story line above and below windows to expose the timber spanners for their equivalent in Later buildings. Next, George screw’s a hook into the top of the building at the center of the wa1l, to which he hangs a “come-a1ong” cable winch. Then after carefully measuring the positions of studs and structural members along the second story line, he transfers these dimensions to two 3″x 10″ oak planks that will be the plates for jacking the building. It is important to use two planks for this purpose so they will flex Like a hinge as jacks lift the building, After double-checking measurements, George hoists the plates into position with the come-along, and lag screws them to the side of the building. SET-UP FOR SILLS Setting up the jacks is often the most time-consuming phase of the jacking process. For the average house, 38′ to 40′ on a side, George will use four jacks to a wall. He positions each jack 24″ off the sill-an angle that is effective for lifting while providing clearance to work at the foundation line. After excavating down to undisturbed earth, George sets a jacking pad of laminated lumber in the angled soil. The 24″- square pad not only spreads the jacking load through a large area of soil, it provides ample room to finesse the jack’s position. On top of the pad comes a block, then the jack and a steel plate. George selects 20-ton hydraulic jacks for most applications. Even though 12-ton jacks are more than strong enough to carry an average frame house, the larger jacks have a longer cylinder throw-on the order of 9″-that allows for more lift without reworking the setup. Also, the bases are larger, distributing the load across a wider area of the pad and increasing support. The 4″x4″ oak posts running between the jacks and the plates on the house have to be measured and cut for each position, and this dimension is subject to how the jack “loads-up” in the soil. When the jacks are tested, loamy soil often compacts for some time before the building starts to rise. Sandy soil, on the other band, tends to load quickly. It takes patience and the experience to “read” the soil around a house and position all jacks optimally. JACKING THEORY In simple terms, the object of jacking is to raise all the house’s low areas so they are level with a benchmark. Typically, this benchmark is a high point in the foundation or central chimney that represents the most stable base in the structure. Jacking helps remove the old sill but, more importantly, it re-establishes the correct height of the floor and wall framing. Originally, the house may have been built on an 8″ square timber -Common practice as late as the 1890s. Over decades, this timber could have shrunk and deteriorated to as little as 6-1/2″ in height. Simply replacing the sill with a new 6″ timber does not regain the building’s original dimensions. Plus, the new material will also settle and shrink in time, bringing sill height down to, say, 5″ -a loss of 3″! Most houses tend to fall or sag towards their centers, so there is usually more distance to jack in the middle of a wall than at the corners. In such a job, this means the jacks will run out of travel or lift capability before the middle is level, and the setup will have to be reworked slightly. Typically, George will extend the middle jacks 9″ or so, then place blocks and shims or cribbing under the studs at the middle of the wa1l. With the house temporarily supported this way, he can collapse the jacks and build up the pad ( or extend the jacking post) to resume jacking. Skeletal Secrets In timber framing, as well as balloon and platform framing, studs, joists, and posts converge along the second-storey line-a structurally stable point to jack. This method also lifts the first-storey walls without putting them under any load, the ideal way to avoid cracking historic plaster finishes. In contrast, jacking at the foundation level risks pushing in the walls. Where bolting a long plate may interfere with mortise joints, George substitutes a jacking pad. TIMBER TECHNOLOGY While the whole point of George’s thorough jacking and leveling of the structure is to avoid piece-meal repairs with short lengths of material, the typical sill job does require splicing sills. No single timber available these days will span the 35′ to 40′ length of most walls, so George makes a 40′ repair with two 22′ timbers. Sill joints have to be as strong as the timber itself, and for this reason George always makes his lap joints no less than 24″ long. He also makes sure the joint is in full contact, inserting a reciprocating saw and trimming both faces at the same time, if necessary. When the fit is correct, 1/2″ lag screws fasten the timbers together. George positions the screws in a staggered pattern, offset by about 1″ so no two fasteners are in line to potentially split the wood, George prefers white oak for many sills, especially for the extra weight of timber frame houses. Since oak is one of the densest woods, he bores 3/8″ pilot holes for the lag screws, as well as 1/2″ holes for the shafts. (Lagging into softwoods requires only a small-diameter pilot hole or none at all.) George’s experience has also taught him to lubricate long lags screw with soap or wax. Otherwise, as these hefty bits of hardware go into the oak, they generate enough heat to seize in the wood halfway down. Before the sill will mate with all the members in the house, it must be cut for the housings and mortises that hold floor joists and studs. Rather than attempt to measure all these pockets to fit the settled, often slightly eccentric dimensions of a 100 or 200 year old building, George lays out the cuts to some standard spacings apparent in the construction, then deals with irregularities as he goes. Though the goal is to have joists rest in pockets as tightly as possible, practicality may call for trimming a joist slightly to get the proper fit. Even with the most perfect of fits, however, maneuvering 22′ of massive oak so it meshes with floating framing takes equal parts skill and experience. George and his crew call on a variety of bars and levers to “shoehorn” the new sill under wall studs and sub flooring. A favorite tool is a flat bar, a tapered piece high-carbon steel that is actually nothing more than a foot or so of truck or car leaf spring. George has several of these tools on hand for inserting under wall studs to make clearance for the sill. Once the new sill is “home,” floor joists and lapped corners secure it in place, ready for the next phases of restoration carpentry. In fact, having the load off the foundation presents “the ideal opportunity for masonry work on the foundation, such as resetting the capstones visible just above grade-the finishing touches on so many 18th- and 19th-century old houses.

]]> http://gyrestorations.com/181/cure-all-sills/feed/ 2 http://gyrestorations.com/112/documenting-historic-restorations/?utm_source=rss&utm_medium=rss&utm_campaign=documenting-historic-restorations http://gyrestorations.com/112/documenting-historic-restorations/#comments Mon, 26 Dec 2011 21:23:22 +0000 george http://gyrestorations.com/?p=112 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 and apply it to the world around them.  I had the pleasure of [...]]]> 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 and apply it to the world around them.  I had the pleasure of meeting and working for a couple in Thurmont MD.  They have spent years restoring there historic home almost single-handedly.  When skilled professional help was needed they took there time and located the right person for the job. I was asked to restore there barn, a late 19c post civil war structure. This barn sat on a substantial **** fieldstone foundation secured with lime mortar.

 All of the corner and exposed wall stones were carefully cut and fit indicating that the person who built this wall was very talented.  The mason that built this wall some 140 years ago was involved in a love affair.  He may not have known that he was, it may just have been a means to survive in these hard times after the war but his work speaks across the decades It tells me that he cared.  The only reason the east wall failed was because of erosion due to a natural change in grade.

 Care is what brings me to the point of this story.

While we were restoring the barn the owners were on a mission to locate someone who knew how to repair their barn foundation.   They invited these contractors to the site to inspect the foundation but no one was interested, no time, no interest, too big a job.  One local contractor did agree to do the work however he said that he would only use Portland cement.  The owners asked me about the Portland and I said I though that would be a problem when it was mated to the original lime mortar foundation. We had meetings with the mason but he wouldn’t budge.  I introduced the owners to John Leeke , as Preservation Consultant out of Portland ME. . John gave them advice on how to proceed with the rebuilding of the wall and to ask if the mason would consider taking a course in lime mortar techniques, when he was asked, the mason still refused even after the owners offered to pay for a course in Chicago.  In desperation the mason was hired because the window to get the work don before sold weather was closing.  

 Having been in this sport for 42 years,  if I have learned anything it’s that  good documentation of a project can help when you can’t remember what it looked like when you started. Although the stonework had nothing to do with me, I knew that the clients wanted to reproduce the walls in question as close to original as possible. I have learned many skills through the years but the most valuable one is documentation through photography.  I always document my own projects start to finish. I’ve also have taken photos of other phases of the project and craftsman that didn’t involve me. As it turned out my photos were the only record of the project showing how work progressed and what was don by everyone on site. The clients were very happy to have the record of the work.

That being said, I took it upon my self to mark all the corner stones with a vertical red crayon line and photograph the corners separately and the walls individually inside and out.  I was sure that the mason would carefully dismantle the walls and line the stones up for reuse. I was wrong; the mason arrived one morning with his crew and pulled the walls down in one fell swoop with a bucket loader/ back how. I was shocked, he then proceeded to scoop up the stones and dump them into a pile. I asked about resetting the corner stones and he said, I don’t really care how they go back together.  At that point we all knew we had the wrong guy.

 After sum frantic phone calls to find a mason with no luck I suggested that the clients give Gordon Bach a call at OHJ, He offered sum names of historic masons and the one from Hagerstown MD. Mr. Douglas Reed was chosen. He came promptly and he was very knowledgeable and said he had a crew that could repair the wall.   The other mason was politely thanked and dismissed.  The owners had access to a company that could blow the pictures of the foundation up to large scale and they were presented when the new masons arrived.  These photos proved very helpful to the masons.  The mason in charge of the actual rebuilding the walls is Tim Winther of Orleans VA. who as it turns out is a master craftsman as you will soon see shortly.  Tim and his helper Adam slowly unraveled the puzzle in the pile of rocks Using the photos and a carefully hand rendered drawing of the walls they pawed through every stone in the pile to locate primary and then secondary stones.

 The photo shows how the previous crew left the walls in a heap.  It took quite a wile to spread the pile out to be able to make some sense of it. Slowly each stone was located on the photo and then found in the pile.  Adam marked the stones that were found and the stones were lined up on the ground in a logical progression. Considering that the stones were being found in random order this took sum creative thinking.  Tim and Adam would decide what stone they wanted to fin d in the photo and then go on the hunt.  As the saying goes, they left no stone unturned.  When this phase of the project was complete the two east walls laid on the ground in progressive order for reassembly. 

By this time the project was becoming more difficult because winter was setting in and lime mortar gets cranky when it gets cold.  The mason team built shelters to harness the suns’ heat and to reduce damage due to cold nights electric blankets were used to protect the mortar until it could cure.  The days were warm enough in the shelter to allow the crew to continue laying stone. The crew worked from mid December till mid March to complete a portion of the north wall and the two east walls. In the end my crew worked two years to complete the barn repair,  completing this project, all turned out well and the clients were very happy.

 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 and said that no contractors would answer his calls and the ones [...]]]> 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 and said that no contractors would answer his calls and the ones that did never showed up to look at the job.  I thanked him for calling and told him I was not available for about a year and that I really didn’t do that kind of work. I told him I had inspections to do that I hadn’t gotten to which had to be finished before I could look at his project.  About six months later I received another call from Jim, asking if I would reconsider and again I politely declined. Jim called a third time and said that the columns were compressing into the plinth blocks and the roof they supported was settling, he asked if would come and look at the problem. Considering it was a emergency I agreed to look at it I arrived at the site on a wet September morning and made my inspection, when I finished Jim and I talked about the situation and possibilities relating to the repairs. Jim asked me if I could do the job and before understanding the consequences of my answer I said yes. His immediate response was, you have the job! The columns were 18′ tall with base parts and capital, that wasn’t too bad The problem with this project had to do with the fact that the columns sat 9′ plus off the ground putting the roof soffit height at 27′. This was the reason that no one else wanted to do the work.

On the two and a half hour ride home I had time to think about the project and come up with a plan. I thought about wood jacking post but realized that the weight and length would be too hard to deal with, that’s when I came up with a new plan, a set of 30′ adjustable jacks.  I took my design my friend who owned a local machine shop, Balgen Machine in West Stockbridge Ma.  I described my design to him and decided on materials and specs and with 4 to 5 weeks they were complete  There is a leap of faith between concept, reality, and application, the moment of truth when everything comes together. That happened in the beginning of November 02. There is a broad learning curve with any new product.   The system consisted of 3 steel pipes sized to fit into one another with alternating pinholes. It was necessary to install support wood between the soffit boards to reinforce the roof plate. A 2×8 PT board was installed to the bottom of the soffit and outside of the frieze board. Two 90 degree saddles were lagged to the PT and the first pipe was installed. Each pipe had to be carefully lifted into position, slid on to the pervious and pinned in place

Ropes attached to cross pins allowed the second and third pipes to be lifted into position safely. We had to make some adjustments to get the proper length. Once that was established the pipes had to be pushed out at the bottom to allow the jack screw and bias to be installed and lowered back into position on top of a 24″ wood P.T. bias.  It took one week to set the jacks up including all of the related prep. When the large screw was turned, the jacks lifted the roof soffit with ease. The roof was jacked to level. We didn’t have a lot of time to pat our selves on the back, the reason we were here was to rescue the columns and we had 3 weeks to do it .

 This is a turn of the century mansion with ornate Greek details, many of which had to be saved. The wood raised deck was removed at the first and second level and a copper roof laid over a fir decking. As with all things, time takes it’s toll. The copper roof at the column base began to leak. The raised seams had to be heated to melt the solder and separated.  All raised paneling and exterior and interior trim was labeled and removed for repair at a later time.

With the roof safely supported a support system was built to hold the second story porch in position and the columns were separated. After considering the difficulty of removing and lowering the columns to the ground we decided to get sum professional help. from Topin Rigging Co  to remove the wood Columns.  The experienced crew strapped and lifted the columns out of position and down to specially built cradle horses that would support them for the winter. This phase of the project took 4 weeks to complete. The building was secured and safety boards were installed at the perimeter of the porch decks for safety and the crew and I were off to Cumberland Island Ga. to save another historic building.

It took January and February to complete our project in Georgia and we started back in Lowell in April. The  roof soffit never moved, I was happy this system worked well.  We spent the next two years on this project restoring decks, railings, and all damaged plinth blocks and bases, the client wouldn’t let us go, he kept finding other work including  the porch on the other side of the house.  Because I said yes to Jim, I had the opportunity to learn how to restore wood columns and that was the gift to myself and my crew.  Jim was happy and we remain friends today.