P.E.bobimm15068

Hello PEbobimn15068,

By your statement, it's pretty obvious that the church roof/wall juncture is in high distress, especially if the top of the wall is deflecting outwards (horizontally?) 2-inches or so.

You could use a strain gage, as someone else has posted, to help measure continuing distress, but I have to ask the question of: Why bother to continue measure something that's already fairly evident, and that the church structural elements are in dire need of stabilization. The sooner the better. My suggestion is not to wait and see if it moves anymore (which could result in structural collapse), but rather to act swiftly and assuredly to solve the gross deficiencies already evident.

You do not mention what the construction materials are in the church, but I would assume that the roof and wall framing are both wood timber?

Over the years as a Structural Engineer (LPE), I've investigated numerous old churches here in the Northeast USA (but mostly in New York State) over the years that exhibited much the same distress as your church is undergoing. Typical of old wooden churches that are over 100 years old, and yes, even newer churches, I've observed that they were constructed with moderate and steep sloping roof framing that was supported solely by the exterior wall framing, but had no horizontal oriented "collar ties" that ran across the interior of the Church to tie the exterior walls together. Several of the churches, and other old wooden structures, like residences and barns actually had failed catastrophically due to heavy snow and ice loadings, whereas some had failed due to high wind loads.

You didn't mention whether there was a noticeable sag in the roof ridge line. The presence of such a sag is also indicative of structural distress and usually accompanies the outward bowing of the top of exterior walls that I described above. Basically,both forms of distress come hand-in-hand with one another. Makes sense doesn't it? Push down on the roof at the ridge line and watch the roof framing (without collar ties or other restraint) literally push the walls outward. Try doing a small scale experiment on your desk using a piece of paper cardboard folded like your church roof and pushing it down with your pointer finger, and watch the results. Pretty obvious what will happen, correct?

Gable roof framing members act as "beam-columns" and impart horizontal and vertical reactions at the top and bottom supports. In this case the top of the exterior wall framing is trying its best to resist the horizontal thrust, just like the base of an arch will thrust outwards. By installing collar ties between the exterior walls, they will aid the walls in resisting horizontal thrust loads acting at the top of the wall. Of course, these collar ties will be in tension. It is equally important to install a new horizontal diaphragm beam of sufficient strength along the top of the exterior walls to help transfer the roof thrusts to the new collar ties.

Hope this helps you out! Have a Happy Thanksgiving!

===CaptMoosie

Thank you. I believe the problem started 25 years ago when they installed a tile roof over the sanctuary, as I would have reccomended an aluminum roof, The tile s 17 pounds each. The building is 150 years old. There is a cathedral ceiling under the roof with a 10 feet space between the peak of the ceiling and the peak of the roof, with horizontal beams holding the arches from outward movement. This is probably what is holding it from collapse now.

I have already told the church management to put in 1.5 inch steel tie bars with a 30 X 30 inch outside plates on the wooden walls and 18 X 18 plates inside with threaded ends on the bars to snug the pates and a turn buckle in the center.

I have a BSIE from Penn State and an MSME from Pitt U. Unfortunately, I lost both legs due to diabetes 1.5 years ago and I am confined to a wheelchair. I still have my P.E license.

Thank you for the comeback

Bob Imm, P.E.

Hello Bob,

First off, welcome to CR4 Forum and Happy Thanksgiving!

Looks like you're on the correct track trying to get the church fixed up!

Sorry to hear about you losing your legs. Basically, you and I are in the same boat, almost. I have Type II Diabetes and almost lost one of my legs 2 1/2 years ago due to very severe infections and ulcers. The surgeon seemed too much in a hurry to cut the leg off...so I fired his butt. BTW, my wife is a RN of 32 years and very proactive as far as one guarding against "Doctor Insensitivity" and the quid pro quo present in hospitals. Actually, I believe I have fired no less than 2 dozen doctors in the last 9 years!!! *LOL* Anyway, thank God both legs have cleared up after intensive wound care services that I received. Also, I have lost about 100 pounds off my max weight, which helps matters some. I still have much more to go and will require bariatric surgery (Lap-Band) to lose the remainder. I'm currently on Disability the past few years and can't wait to get out and work full-time again. Currently it's still very difficult to get around due to the acute leg pain that never seems to leave...hopefully soon!

I've probably disclosed too much already here in open forum, but I really don't care if others may think unkind thoughts, etc.

Have a great evening Bob, and nice to have met you!

You're looking to detect future/continuing movement, right? (As opposed to simply measuring what has already occurred.)

You probably need something like an electrolytic tilt sensor, or inclinometer. You can read more about them here:  http://www.educypedia.be/electronics/sensortit.htm

If commercial systems are out of your price range, I would check with the microcontroller DIY community through the Arduino or PIC forums. A lot of these folks are amazingly imaginative, and would love to help with such a project.