City of Ojai, CA Material Requirements

(a)

General. All URM walls utilized to carry vertical loads or seismic forces parallel and perpendicular to the wall plane shall be tested as specified in this section. All masonry that does not meet or exceed the minimums standards established by this chapter shall be removed and replaced by new materials or, alternatively, shall have its structural functions replaced by new materials and anchored to supporting elements.

(b)

Lay-up of multiple wythe URM walls. The facing and backing shall be bonded so that not less than 10% of the exposed face area is composed of solid headers extending not less than four inches into the backing, the clear distance between adjacent full-length headers shall not exceed 24 inches vertically or horizontally. Where the backing consists of two or more wythes, the headers shall extend not less than four inches into the most distant wythe or the backing wythes shall be bonded together with separate headers whose area and spacing conform to the foregoing. Wythes of walls not bonded as described above shall be considered as veneer. The veneer wythe shall not be included in the effective thickness used in calculating the height to thickness and the shear capacity of the wall.

(c)

Mortar.

(1)

Tests. The quality of mortar in all unreinforced brick and hollow clay tile masonry walls shall be determined by performing in-place shear tests in accordance with Uniform Building Code Standard 24-7. Alternative methods of testing shall be approved by the Building Official for other types of masonry wall construction.

(2)

Location of tests. The shear tests shall be taken at locations representative of the mortar conditions throughout the entire building, taking into account variations in workmanship at different building height levels, variations in weathering of the exterior surfaces and variations in the conditions of the interior surfaces due to deterioration caused by leaks and condensation of water and/or by the deleterious effects of other substances contained within the building. The exact test location shall be determined at the building site by the engineer in responsible charge of the structural design work. An accurate record of all such tests and their location in the building shall be recorded and these results shall be submitted to the Building Official for approval as part of the structural analysis.

(3)

Number of tests. The minimum number of tests per class shall be as follows:

(i)

At each of both the first and top stories, not less than two per wall or line of wall elements providing a common line of resistance to lateral forces.

(ii)

At each of all other stories, not less than one per wall or line of wall elements providing a common line of resistance to lateral forces.

(iii)

In any case, not less than one per 1,500 square feet of all surface nor less than a total of eight.

(4)

Minimum quality mortar.

(i)

Mortar shear test values, Vto, in psi shall be obtained for each in-place shear test in accordance with the following equation:

V_to = (V_test - P_D+L)/A_b

(ii)

Individual URM walls with Vto consistently less than 30 psi shall be entirely pointed prior to retesting.

(iii)

The mortar shear strength, Vt, shall be the value in psi that is exceeded by 80% of all of the mortar shear test values, Vto.

(iv)

Unreinforced masonry with mortar shear strength, Vt, less than 30 psi shall be removed or pointed and retested.

(5)

Collar joints. The collar joints shall be inspected at the test locations during each in-place shear test and estimates of the percentage of the surfaces of adjacent wythes which are covered with mortar shall be reported along with the results of the in-place shear tests.

(6)

Pointing. All deteriorated mortar joints in URM walls shall be pointed according to Uniform Building Code Standard No. 24-9. Nothing shall prevent pointing with mortar of all the masonry wall joints before the tests are made.

(§ 1, Ord. 678, eff. July 12, 1991)