# Sill plates on top of brick



## Skinny (Mar 25, 2012)

Hi All,
I am replacing mud sills on a hundred year old home. The foundation is hard packed sand on top of which a 4 inch or so footer was poured and then a double brick wall was built. The house was then built on top of the double brick wall. They had a bed of mortar laid on top of the double brick and the old sill plate was placed on top of the mortar. The sills are rotted and termite damaged and the old mortar 'bed' is now cracked and or missing in several places. This original mortar bed is only 5/8-3/4 of an inch currently but was probably thicker when first applied. My question is, when I replace the sills, should I have another bed of mortar laid first or just clean the brick off, lay down air barrier and place the new P/T sills on top of that? Wouldn't the new mortar 'bed' just re crack with the weight of the house or is there a special mortar that would handle this? There are no other foundation issues, the brick walls are in exceptional shape and only a very minimal amount of settling given the age of the house. Any advice on best approach would be appreciated. Thanks!!


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## AustinDB (Sep 11, 2006)

if the mortar was 5/8-3/4 initially I suspect its always been that thickness once the initial curing of the mortar was complete. None the less, if there is a double wall and it's in good condition, I would have a clause in my contract regarding the condition and subsequent issues related to not placing a proper foundation under this 'fix'. Seems like a very thin bed of mortar would be necessary for weight distribution on an uneven brick surface. How is the sill plate connected to the brick? May need to install tie downs every 4' and grout them in place. Wouldn't code require you to install them on this type of project?


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## dom-mas (Nov 26, 2011)

Mortar is commonly used between sill plates and foundations. A type "S" mortar,whch is a structural mortar, should be fine You could use several layers of gasket seal, but the mortar bed will stop point loading.


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## Skinny (Mar 25, 2012)

Thank you both for taking the time to answer. It makes sense to reapply a new bed to spread the load evenly and help level out any minor issues. The old brick mortar is soft lime but I take it that since this is a top bed for a sill plate the type S would be the way to go. I know you don't re point with S over soft lime but that's really not what we are doing here, right?


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## dom-mas (Nov 26, 2011)

Exactly. While a lime mortar would probably suffice there is no harm in using a much harder mortar since it won't stop the brick from breathing at all.


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## Skinny (Mar 25, 2012)

Sounds good. Thanks again for the help!


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