stone veneer and weep holes

House was built in 2008 and has real stone veneer on part of the home. There are no readily-visible drainiage provisions as you would find with brick. Using the 2000 IRC R703.7, it states that “All stone and masonry veneer shall be installed in accordance with this chapter, Table R703.4 and Figure R703.7…”

Looking at figure R703.7, it clearly shows weepholes. And, R703.7.6 (located in “this chapter”) states necessity of weepholes.

Local code enforcement states weeps are necessary on stone veneer. I got mixed answers from other contractors and home inspectors.

Now, this house is a new construction foreclosure. Bank took it over and a contractor was assigned to make repairs from my report. Contractor stated that the stone manufacturer said specific weeps are not necessary when gaps are intentionally left in the mortar between stones as gaps serve as weeps. That makes sense to some degree and mortar is not real tight on this home; gaps present in random places.

However, weeps are supposed to be placed immediately above the flashing. So, I would think I would see a horizontal line in the stone where the bottom of stone, and mortar gaps, would serve as weeps (make sense?) I don’t see any planned break or purposeful patten to the stone where the flashing would be.

What do you think?

Weep screed should be where house framing meets the foundation. Yes, there should be a horizontal line that would indicate its presence.

The state of NC “recommends” that home inspectors use the language below to describe the defect.

"Manufactured stone veneer has been installed on the front of the home of this house. An inspection of the visible components has revealed that the stone veneer has not been installed in compliance with installation guidelines provided by the Masonry Veneer Manufacturer’s Association (MVMA). (A PDF copy of the installation guidelines is available on our website.)

Specific problems noted with the visible components include, but may not be limited to (select all that apply):

  • Weep screeds are missing at the base of the wood frame walls.
  • Weep screeds are missing at the tops of window and door openings.
  • There is no caulk between other materials and the masonry veneer at windows, doors, and adjacent trim.
  • The masonry veneer is in contact with the ground.
  • The masonry veneer is in contact with paved surfaces.
  • The masonry veneer is in contact with roofing materials.
  • Kick-out flashings are missing where roof eaves meet the masonry veneer. Metal lath is visible between stones, indicating that the proper base coats of mortar were not applied prior to installation of the stone.

The lack of proper detailing and flashing may result in water penetration behind the siding, resulting in structural damage. The installation of the manufactured stone veneer should be evaluated, compared to the specific installation requirements of the stone manufacturer and the MVMA, and repaired or replaced as deemed necessary by a licensed general contractor or masonry contractor experienced with installation requirements for manufactured stone veneer.

Please note that because the water resistive barrier, metal lath, and base coat(s) of cement stucco are completely concealed behind the manufactured stone veneer, they cannot be evaluated by a visual inspection."

If it’s real stone, you can modify the statement above to delete references to manufacturer instructions. The same principal applies.

This is not pre-cast stone. I am fully aware of that material and requirements (I use the MVMA document: and the same statement you just posted).

This is real stone.

Are you sure?

The same principal applies. All siding types should have a drainage plane.

That is what I think but this is the second builder to say no and code folks did not require it (not necessarily a surprise there).

Where are you located, Ethopia?

NC. I guess you’d be surprised. On new construction I regularly find broken trusses, missing flashing, over fused breakers, open live wires in crawl spaces, etc.

I’m a code enforcement officer, and I require it. Most others are ignorant of the issue. Just not enough training for municipal employees. A stone veneer wall is nothing more than lumpy stucco.


A Few Applicable codes (2006 International Residential Code):

**R703.6 Exterior plaster. **Installation of these materials shall be in compliance withASTMC926 andASTMC1063 and the provisions of this code.

**"R703.6.2 Plaster. On wood-frame construction with an on-grade floor slab system, exterior plaster shall be applied to cover, but not extend below, lath, paper and screed."
*Keyword: “screed”. i.e, drainage system.

*** **“R703.6.2.1 Weep screeds. **A minimum 0.019-inch (0.5 mm) (No. 26 galvanized sheet gage), corrosion-resistant weep screed or plastic weep screed, with a minimum vertical attachment flange of 31/2 inches (89 mm) shall be provided at or below the foundation plate line on exterior stud walls in accordance with ASTM C 926. The weep screed shall be placed a minimum of 4 inches (102 mm) above the earth or 2 inches (51 mm) above paved areas and shall be of a type that will allow trapped water to drain to the exterior of the building. The weather-resistant barrier shall lap the attachment flange. The exterior lath shall cover and terminate on the attachment flange of the weep screed.”
***Keywords: “shall”, “screeds”, “2 inches above paved areas”, “4 inches above earth”

*** **“R703.8 Flashing. **Approved corrosion-resistant flashing shall be applied shingle-fashion in such a manner to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend to the surface of the exterior wall finish. Approved corrosion-resistant flashings shall be installed at all of the following locations: 1. Exterior window and door openings. Flashing at exterior window and door openings shall extend to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage.
2. At the intersection of chimneys or other masonry construction with frame or stucco walls, with projecting lips on both sides under stucco copings.
3. Under and at the ends of masonry, wood or metal copings and sills.
4. Continuously above all projecting wood trim.
5. Where exterior porches, decks or stairs attach to a wall or floor assembly of wood-frame construction.
6. At wall and roof intersections.
7. At built-in gutters.”
Keywords: “shall extend to the surface” i.e., shall be visible, "shall be installed at all of the following locations"

That makes sense. Since 2009 they have been installing weep screeds but often lack the other details when using the manufactured stone. Thank you for the info.

I have never seen pre-cast stone done correctly.

The OP indicated real stone with an air gap between the stone and the house. This is really just like a brick installation. Weep holes may or may not be required by the local AHJ.

What’s an OP? Where do you see reference to an air gap?

I thought the OP (original post) indicated an air gap but I guess not.

The only real stone I have seen on a house was installed just like brick with an air gap. Its the best way to do it and I assumed it in this case. I was able to verify the air gap method on that particular house.

It would be hard to see the gap unless you looked in the right places, it may not be visible at this point. I would be careful condeming an installation of real stone without all the facts.

Bruce, I don’t see any way to make a flagstone wall like that unless it’s stuck to the underlying substrate.

I agree, the real stone I have seen was much thicker.

Looking at the thickness of the stone on the exterior corner, it looks like Natural Stone veneer. But could be wrong.

Natural stone veneers are usually 1" to 1-1/2" thick. Hard to tell from photo, but looks thicker than thin natural stone.
In any case if that is what it is, this video might help.

Bruce, flagstone is real stone.