infilling an existing CMU wall with CMU

[mauri10]

Need to infill with CMU some openings in an existing CMU wall. Do you have a procedure/detail to share?. The building was built in 1972

 

[msquared48]

Depending on how you do the infill, the stiffness of the wall may be increased.

Are you looking to increase the wall stiffness for extra needed lateral capacity, or just fill in the walls for Architectural concerns?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[SLTA]

A 1972 building may or may not have mortar as strong as today. Make sure you're not creating a hard pocket in the wall that will bust the existing blocks.

How big is your hole to infill? And why are you infilling it, like Mike asked?

 

[mauri10]

CMU infills are for architectural reasons, walls been infilled are not part of the lateral resisting system (only out of plane lodas)
Openings are 8.5'Hx7'W and 7'Hx28'W
Given the uncertainties in the exisitng cmu surrounding the openings, would it make sense to demo top and bottom of openings are build a new CMU wall spaning from floor to roof?

 

[SLTA]

Not sure that's needed... and it would no longer be "infill" then.

28 ft long is HUGE. If that's right, make sure there are expansion and contraction joints in the new parts, to deal with the aging of the new block.

 

[concretemasonry]

Mauri10 -

Don't worry about the strength of the mortar since the over-all wall is currently adequate structurally.

The first appendix item of ASTM C90 for mortar recommends using the weakest mortar possible to carry the loads (stronger mortars sacrifice other properties) which would be minimal unless additional loads were created by making "hard/strong" sections in the wall that attract loads.

As a guess, Types N or S mortars would be adequate, but Type M would be unlikely.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[dabiz97]

Hi, dredging up this thread I just came across, I need to fill in several CMU walls for architectural reasons (typically about 10'x10' openings in a 27' tall 8" CMU grouted wall). My question is: what is the actual procedure to tie the new in-fill wall in at all four sides (or do you not tie into the top?).

I don't know if I'm lacking imagination or if this is really tricky to do. I can see embedding bond beam bars each side, and vertical bars into my footing, but how do you slide blocks in and still tie steel to the bottom course of the existing lintel above?

Do I not need to bother with that, considering this will not be a shear wall? Still, how do I grout cells and finish the top course? Any pointing in the right direction would be appreciated.