Replies

1. 
   darcey | Nov 11, 2004 09:48am | #1

   Bump!

   Brian,

   I am bumping your thread up due to the lack of responses.  (It never got noticed maybe...)  I am sure you will get some responses soon.

   In any case, it appears that you are the 50,000th poster!  Congratulations!  If I were you I would write FHB and at least request a pencil or t-shirt or hat...

   Good luck with your project!

1. 
   homebaseboston | Nov 11, 2004 04:19pm | #2

   Thanks Darcy, much obliged.  Was too embarrassed to do it myself and may have to go at the project as soon as this weekend!

   Wow, 50,000.  Think I'd have to defer any gifts to Piffin, Stan Foster, Notchman, Jim Blodgett, Cloud, Boss, Mike Smith, MrT... or one of the other "bedrock" members who've helped so many folks -- particularly myself -- over the years. 

   Andy, in honor of this momentous occassion, please ask Tauton to make a donation to the charity/brewery of their choice!

   Brian_____________________________HomeBase__________________________  LLC

2. 
   rvillaume | Nov 11, 2004 04:32pm | #3

   Your mason is right, although I would tend to go the other way for exterior work - I'd use portland with some Type S added in, say 2 shovels of the mortar per bag of portland.  

   Sounds like you're going to be mostly pointing things up, and for stonework you want to use a pretty stiff mix.  As long as you can get several hours of above freezing temps, and it doesn't dip into the teens at night you'll get enough of a set that you don't need to worry about the mortar freezing.  Chisel, hammer and scrape back the old mortar back to where it's pretty solid.  If you're trying to match the color of the old stuff, if it's like the stuff on my house (+- 200yrs), you might have to get a bag of white portland or white mortar.

   I've never used a bonding agent except when going over old concrete and doesn't seem like you'd need it here, except if the joints are really large and there's gonna be a lot of bonding to the old mortar.  You don't need it for the stones.  If you do use it, the bonding agent can't freeze or it loses its purpose.

   Have no favorite brands, but different brands do dry out to different colors, so again, if that's an issue, most masonry supply places have samples of the dried color.

   Good luck with it. 

3. 
   PaulBriggs | Nov 11, 2004 06:07pm | #4

   I work full time as a historic restoration mason and I specialize in 19th century mortar reproduction. Your home PROBABLY is straight lime mortar and you should use the same or at the very most 1 part portland to 4 parts lime in the mortar to repair it, EXCEPT for the fact that we're facing freezing weather here. That is a problem. You will never have a portland mix match the appearance of the rest of the mortar and a high portland mix will expand and contract differently over the years (Less expansion than the old) and it will crack in places as well as always look unsightly. There's nothing worse looking than the lurid patches of portland cement on old masonry for generations to come. The ideal thing is to use temporary great stuff foam or to stuff insulation around til spring comes and then remove it and match the original mortar- composition, color, weathering and all. You can e-mail me on how to do that if you are interested. You may not care all that much however, so I understand that.  If you do, then the least you should do is repoint with no more than say 1 part portland, 3 parts hydrated lime, (sold in farm and garden supplies for $6 a 50 lb bag.) and 11 parts sand (a mix of fine and coarse sand with roughly 2 fine to 1 coarse ratio) Leave the joint recessed and brush smears and messes away before it dries. Repoint in the spring with a mortar which matches the old wall.  Make sure that you have at least 2 days and nights above freezing. Hose off the stone and old mortar joints and don't use a bonder as they usually do poorly below 50 degrees. Smear some wetter mix thoroughly onto the repointing area with a rubber gloved hand and then repoint while that is damp.  My email is [email protected]

1. 
   homebaseboston | Nov 12, 2004 12:56am | #5

   Paul, thanks.  I'm going to email you seperately, but I thought I'd ask for the benefit of the forum:  How does lime mortar perform from a 'structural' stand point... i.e. compressive strength/flexibility etc?

   I'm not terribly worried about the appearance... more about the cracking and expansion/contraction.  I've only got a few bearing points now holding up the sills, so I'm anxious to get something under there in the coming weeks if possible.  Looking forward to connecting in more detail

   Brian_____________________________HomeBase__________________________  LLC

4. 
   rbishop108 | Nov 12, 2004 01:14am | #6

   one 94 lb bag of portland white cement (if white matches, grey otherwise)

   two 50 lb bags of lime

   four 5 gallon pails of sand

   reduce the mix accordingly to make a batch that you'll use fairly quickly (1 - 2 hrs)

   I get a gallon of Anti-Hydro, and a gallon of Acryl 60 or equivalent and mix them together.

   Put a tall coffee cup full of this mix into a pail of water, use this to mix the batch with.

   Mix it stiff, it will be a bit sticky. Stuff the joints with the mortar, don't worry about the finished look yet. Just stuff away for about 20 min or so, then come back to the begining and start adding/smoothing over to finish the joint.

   Put insulation, then a moving blanket, then poly to keep the breeze and coldness off of it. Maybe you can throw some heat to it from the backside, something low and steady, not hot & strong. Just have to keep it from freezing. The Anti-Hydro helps with this, but the wind will get you every time. Keep the breeze off of it and you'll be fine.

   I wouldn't want to do a whole house foundation like this, this time of year, but..........

   If you're just fixin a bit of it, you're good to go.

   Rod