DIY Home Improvement Forum banner

Repoint and Parge basement brick walls

2181 Views 3 Replies 3 Participants Last post by  UpstateNewYorke
I have a home that was built in 1939 and a basement that was previously finished in the 1970's. I have removed the walls because the prior owner had put insulation up against the brick walls. This led to some nice mold and wet insulation which I noticed after I moved in.

My basement was wet during the springtime when I bought the house, but I have since fixed issues outside (gutters, etc...), and it is dry. I do run a humidifier during the summer.

I would like to repair the brick walls and potentially finish the basement the right way. Are there any recommendations for a mortar mix for repointing the brickwork and then a mix for parging. I have seen alot of talk about older homes, but not so many for newer homes like my 1939 home.

What I have seen for homes built before 1930ish:
For repointing use a lime based mix, maybe 1:2:6 (portland :lime: sand)
Next parge over with a slightly softer and richer mix say 1:2.5:8.
Then use something like drylok to water seal the brick.

Any thoughts from those that may have done this before? A photo of the basement is attached. You can see it is a mix of painted brick, sections that were previously parged, and exposed brick.



See less See more
1 - 1 of 4 Posts
Yes you should repoint any mortar joints that show failure.
The correct mix to use for repointing should match the existing in make up & PSI for this you may need to have a sample tested by a lab. Also the repair mortar should be weaker than the softest brick. A type "N" mortar was most likely a standard mix in 1939.
Using todays standards a Type "S" mortar is required below grade keep in mind that this mix is rated @ 1800 PSI which is double the Type "N" mortar.
To parge the existing walls as seen in the photo Any parge mortar use will only be as good as the paint / existing white coating that is now on the brick.
Mortar will not adhere well to a painted surface & will fail over time.
Only after you are sure the water / moisture problem is taken care of you can
apply a coating over the existing Exposed brick , parged brick & painted brick using a Synthetic base coat material Like STO Corp. RFP than use a Synthetic finish coat texture & color as you select.
Please note the RFP material is not a high build base coating so you can not level out the wall with this type coating a reason you may need to texture it.
See less See more
  • Like
Reactions: 2
1 - 1 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.