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QUESTION: Is waterproofing of the entire block structure prior to the brick installation a code requirement in New Jersey and if yes, what materials should be used?

Is waterproof of the crawl space inside (walls, floor, ceiling) and out a code requirement in New Jersey and if it is, what waterproof materials should be used?

Thanks for your help.

ANSWER: Thank you for your question, Nur, this is what I understand:
You have a brick wall with a structural CMU backup wall, correct?  I assume the brick is a veneer connected to the CMU  with brick ties.  If that is the case, then yes you need a 'water resistant barrier'.  Given the nature of the construction, a liquid applied type would be the only effective type.  Sheet barriers would be impossible to install over the brick ties which are already embedded in the CMU.  The International Building Code dictates a water resistant barrier. behind your finish layer. CMU is naturally porous and would be a sponge for any moisture that made its way through the brick, and believe me, water can and will get through the brick.  I also hope you plan to have at a 1" airspace between brick and CMU, have a ledge with through wall flashing and weeps at the base of the brick at 48" o.c with weep screeds.  I also hope you have a vent at the top of the airspace to equalize the pressure in this cavity.  A silane or siloxane sealer on the brick is advisable.

Your crawlspace will require a 6mil minimum vapor barrier over the soil to prevent the moist soil from releasing moisture to the warm floor above.  Steggowrap is an excellent choice since it is tear resistant and has an array of tapes and flashings... or the economy version is 10 mil visqueen, a bit sturdier than the 6 mil.  All  joints should be taped as any penetration or gap or joint would negate you having to install it at all. Be careful to repair any penetrations.

Things are different if you have a heated crawl space, however, which I assume this is not.

Hope that helps.

---------- FOLLOW-UP ----------

QUESTION: thank you so much for your answer.  Please give me a link to the website where it says exactly about waterproofing of the entire structure not just a crawl space because my vuilder deos not want to waterproof it.

Hope you reply soon because they have started bricks


One caveat:  All masonry construction is considered by the code different in regards to water barrier and there is not likely a code requirement for masonry or concrete for a drainage plane, however, it is certainly good construction practice.  I will respond again when I get back to the office to verify and send relevant code references.  I also should mention I can not comment on code requirements of other States.

With the time zone change I have not had a chance to get back to my office to review IBC Code sections and provide actual code sections to you.  I will also send info on 'good construction practices' for masonry. My apologies for sending this out before doing so.  There is a time difference so it may be a few hours.  I would also be interested in what type of occupancy is inside, if a stud wall and finishes are planned inside and if a vapor barrier is planned.

Thank you for additional info and please verify the total wall construction, and IF THE AIRSPACE IS A CAVITY OR FILLED WITH GROUT as your original email did not elaborate.
Thank  you

Here is the IBC 2012 on Weather Protection section 1403. Exterior walls require a 'water resistive barrier' per section 1403.2 however Exception 1 exempts concrete and masonry walls.  If you have CMU behind the brick and if the CMU wall is constructed according to the practices defined in chapter 21, then you do not need a 'water resistive barrier'.  Chapter 21 is basically the standard methods of construction for CMU.

THE CODE IS NOT SPECIFIC ON WATER BARRIERS FOR BRICK VENEER ON MASONRY WALLS but the data on construction practice is suggests a water resistive barrier for anchored masonry veneer on CMU WITH AN AIRSPACE cavity.

In regards to 'good construction practice' Here are some references for that.
the root web site is:
see 'Detailing, Through wall flashing' references a Water resistant barrier.  


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Albert A. de Santis


Value: best choice for design value and longevity. Design: planning, plan vs reality, elegant detailing, Poetics of Architecture, Japanese Architecture, modern design. 'Green': the hype vs reality, shopping and selection tips. Construction: materials and methods, estimating tips, sequencing, other tips. Color and finsihes: how to shop, how to select, and DIY tips. Cost: estimating tips.


I have learned and applied 'green' design before the term was coined. I was Educated in 1990 by Volker Hartkopf and Vivian Loftness at Carnegie Mellon (leaders in Sustainable and integrated systems) and having personally built (as a Contractor) projects with sustainable strategies and reused materials. I have personally designed, detailed, and supervised construction of hundreds of thousands of square feet of small residences to College buildings, Offices, Clinics, and Churches. I am well read in design theory, especially Japanese design. I have travelled to Japan dozens of times.

Architectural degree from Carnegie Mellon, 1990

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