Home>Discussions>EXTERIORS>Help! "beasties" eating mortar on brick portico columns
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Help! "beasties" eating mortar on brick portico columns

I live in a 1925 brick, craftsman bungalow in Memphis, TN. This brick/mortar problem has puzzled some old-timer masons and the state agricultural extension service.The roof of the porch extends over the driveway to form a portico, supported by two square brick columns. Every year with the start of warm weather, some sort of beasties/insects have been gradually "eating" into the mortar. They are not visible but they have already eaten the mortar about an inch into the columns, leaving a fine dust between the bricks. (see pics) I have tried insecticides and bleach to now avail. (see pic). Do you know of a remedy for Mortar-Eating-Beasties, or can you refer me to another source, Please? I assure you this is NOT a case of the mortar just being old. There is no evidence of this anywhere else on the house. Sorry, wasn't able to upload pics. Thanks for your help!

Re: Help! "beasties" eating mortar on brick portico columns

I have never heard of mortar eating insects and I doubt if there are any. It sounds like you have deteriorating mortar. The fact that it only happens at the column suggests that is where a bad mix was used. Water splashing up from the drive could help accelerate it.
I can't believe the mason hasn't told you this. If that much mortar is missing why don't you repoint the joints and be done with it.

Re: Help! "beasties" eating mortar on brick portico columns

Your problem is MOISTURE.
There are not any insects that will attact lime mortar.
Also the bleach will do more harm than good on any mortar.
Pesticides may also harm the mortar.
See if you can research a find the following.
LIME in BUILDING by Jane Schofield 1994
Also check this booklet Masonry Decay Published by Technical Conservation Research Historic Scotland.
Check with the National Park Service in your area they will have info on mortar joint repair material also read up on the Preservation Briefs Preservation Assistance Division

Re: Help! "beasties" eating mortar on brick portico columns

Mix Sevin insecticide dust into the new mortar, that'll fix 'em. Or hire an invisible exterminator for the invisible cement-consuming bugs.

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