Jim43

MJR6550, Wood walls would pull in. Cinder block walls will be damaged if completely PULLED in. There is no way to know from behind our computers how firmly the roof is attached to the CINDER BLOCK walls, or what kind of cracks are already in the mortar joints; but the roof may be very securely attached. Even with ONLY a friction "attachment", the CINDER BLOCK walls will be damaged if you try to completely pull in the walls that took 5o years to get where there are. The house was built improperly (ceiling joist direction versus ridge direction). There are too many unknowns to RISK anything but taking the outward pressure off the walls, which will allow the walls to straighten up somewhat, and is a very good thing to do (and the house will last another 50 years). Keep It Simple, and safe. (I did not take the time to do the calculations for his house. For my 2 story garage I will just pull in the WOOD/ Vinyl walls until they are straight and won't need to know if I am using 1000 pounds or 2000 pounds each of only 4 cables across the knotty pine paneled great room. My real problem is one end of my 26 foot long unsupported "ridge" beam is "supported"/built over a 6' doorwall with NO header over the doorwall. The doorwall/garage needs a 18 foot long, double 2x12 header over the doorwall, to span the garage door that is below on the first floor of the garage. Much more involved than just pulling in 2 walls with cables.) Jim43

Wood rafter ties will carry no load (will be useless- do NO GOOD) UNLESS you have some means to actually load the ties in tension by first jacking up the ridge 4 inches before you attach the rafter ties to the rafters, or otherwise move the bottom of the rafters toward the center of the house 1/2 inch before attaching the rafter ties. (Do NOT do EITHER one because you will destroy the house trying to improve it.) 1. Aircraft cable with steel/ stainless steel turnbuckles is a good idea (I plan to do this to my garage with a 26' unsupported ridge and 2" sag with a similar pitch; my WOOD walls are bowed 1" on one side and 3/4" on other side, measured by stretching a string from end to end). 2. Heavier cable (2000 to 8000 pound working load) than you thought you needed is necessary because the lighter (5/32" or 3/16") cable will stretch (experience) so much, your turnbuckles will run out of travel before you do any good. 3. Take some careful measurements BEFORE you start, so you know EXACTLY the distance between the walls, and exactly the distance between known points on the rafters (distance from lower end of rafter on one side of house to lower end on other side- drive thin screws or nails perpendicular into side of rafter so measurements will be precise and "repeatable"- WRITE the measurement ON each rafter). Just a wild GUESS, but this distance MAY decrease 1/4" when cable is fully tensioned. Cable when tensioned may sound like a very low bass fiddle when thumped; but NOT like a guitar. Remember that you have more than one cable, so 500 pounds of tension on each cable times 20 rafters would be 10,000 pounds of inward force which sounds like a lot- maybe too much, or much too much. Re-calculate tension per cable assuming just the weight of 16" or 24" linear length of roof and shingles PER RAFTER. Too little tension would be much better than too much tension. Maybe you only need a cable every other rafter. 4. For attaching the cable to the rafters, you might consider drilling a perpendicular hole approximately 1 inch in diameter (barely big enough for your iron) thru the rafter (as close to the outer end of the rafter and as close to the roof as is practical) and inserting a 5 inch long piece of iron (1/2 inch steel water pipe is cheap). Form a loop in the end of the cable with a cable clamp, and loop the cable up and outward over the pipe on BOTH sides of the rafter. You will need to protect the bottom of rafter where the cable passes under the rafter- I suggest the metal plates from the electrical department at Home Depot/ Lowes that are used to protect electrical wiring in walls. $.40 each. Ask in the store. http://www.homedepot.com/p/Halex-1-1-2- ... /100151742 4. Get GOOD (steel/ stainless steel) turnbuckles that will carry twice the load needed/ cable about 10 times the load). Tighten the turnbuckles to take ALL the side thrust off the walls (this will be an estimate on your part; the walls MAY move SLIGHTLY toward the center of the house when you relieve the outward side thrust load, which is OK, but do not PULL the walls together. If you tighten more than just taking the side load off the walls, you run the risk of cracking the walls, and reducing the strength of the walls. Just relieve the outward thrust, and no more. This MAY remove perhaps 1/4 of the ridge sag. If you remove all the ridge sag, you will damage the outside walls doing that. What you are trying to do is relieve all, OR MOST, of the side load on the walls, so it MAINTAINS the current position. Wood walls you could pull back a little; block walls you will damage if you try to pull them back. 5. Do this over time: relieve 40% side load initially, 10% more each week for 6 weeks. In a year, you could check your MEASUREMENTS, and give the turnbuckles one or two more turns as needed to maintain the planned distance. 6. The goal is to relieve the pressure, so it does not get worse; NOT to pull the house back together. Good Luck, and tell us how it came out. 7. this link is too much unrelated information about unevenly loaded masonry basement walls, but may explain why you do not want inward, OR outward pressure, on your block walls- the load should be only straight down. http://ezinearticles.com/?Are-Your-Base ... id=1519592 . Jim43