I've never heard of OPC causing wood rot. The ends of joists are wrapped if put into the older solid brick walls where they could be in contact with damp brickwork.
However the timber roof plates are bedded on the inner block walls with OPC mortar. The main issue is dampness.

 

wood rot

I agree with Stuart45,never heard of opc causing a problem with wood. As stated, to wrap the ends of wood placed in brick pockets is good practice,it prevents wicking of moisture. I would prefer a peal and stick membrane as in Grace Ice & Water Shield,it would provide a better seal at laps. Another method used in heavy timbers was the Goetz-Mitchell anchor,it provided an air space to prevent rot,and apositive connection to help create the building diaphram along with a way for the member to "drop" out of the wall in a fire event without turning the wall over. see item 226


http://chestofbooks.com/architecture/Building-Construction-V2/Slow-Burning-Construction-Part-2.html

 

along with a way for the member to "drop" out of the wall in a fire event without turning the wall over. see item 226


http://chestofbooks.com/architecture/Building-Construction-V2/Slow-Burning-Construction-Part-2.html

They used to cut the ends of beams and joists at an angle in old mills around here for the same purpose.

And i agree with the others who say that the portland doesn't cause rot, the wicking does. Lime is actually antibacterial and when used as whitewash is a wood preservative. (not sure if portalnd has the same properties)

 

^^Always used ice and water shield for separation.. Unless for expansion and that's classified.

 

Good building practice. Ive even used some lead if I didnt have anything else handy for a beam.

 

really??? You had sheet lead hand but no blueskin??? Can't buy lead here anywhere. I was supposed to supply lead cpoated copper chimney caps for a contract on a bunch of chimneys. Ended up having to use zinc coated 'cause no one would supply the lead coated

 

Ya there are hundreds and thousands of 50 pound rolls of 8,10,12 inch lead even at lowes and home depot lol. How else would you flash a chimney? Copper !

 

galvanised step flashing, then painted steel? At least i guess that's what I get. i just ask for step flashing, then go to the sheet metal place and give them the dimensions and they supply me with the finished flashing in my colour choice. whatever i get, I know it's not lead

 

Lead

With lead coated copper

 

With lead coated copper

How would that work at the scrap yard?

 

Lead

Lead melts at 850Deg f. you could melt it off and give the junkman a choice,do you want to buy the lead,copper or both?

 

Lead melts at 850Deg f. you could melt it off and give the junkman a choice,do you want to buy the lead,copper or both?

Thanks, good to know

 

That angle is the fire-cut - mandatory when your bearing on solid masonry. Don't wanna push out the exterior walls on the firefighters during collapse and cause additional damage to the structure.

Just for the record,...I live in a 2 wythe home of 4" block and 4" clay brick and when I remodeled the bathroom, I had about 12 floor joists which I doubled and cut in next to the original pocketed ones. All were in perfect condition with no protection. They didn't forget to fire-cut though :whistling

 

Floor joists

In the days that solid masonry bearing walls were prevelent, a fire cut was required on joist ends since 1860.The fire cut was approx.a 30degree cut starting at top of joist just at inner face of wall. To also add stability to the building anchor bolts/rods went from bottom edge of joist to exterior face of wall. On strictly utilitarian buildings a steel pin went through an eye on the end to prevent withdrawl. On "fancy" buildings the end was provided with a decorative cast medallion. The Goetz-Mitchell anchor addressed these needs,while the aforementioned system was used on light framing. For those interested scroll through the link provided.

http://www.gobrick.com/Portals/25/docs/Technical Notes/TN44.pdf

 

Flashing

While we are talking flashing material,one material that is a big nono is aluminum. Mortar contact with aluminum is the kiss of death for it.Mortar will start to attack aluminum before the scaffolding is on the truck.

 

While we are talking flashing material,one material that is a big nono is aluminum. Mortar contact with aluminum is the kiss of death for it.Mortar will start to attack aluminum before the scaffolding is on the truck.

unless it's painted I believe, all 4 sides of course. i think we've all seen the immediate damage mortar can do to aluminum thresholds