KESCORP

Knight Engineering Services

1210 Hamblen Road . Suite 200 o Kingwood . Texas 77339 o (713) 359-6431

December 7, 1989

Aetna Casualty & Surety
P. O. Box 911
Houston, Texas 77001

Attention:
Ms. Phyllis Hoffpauir

Reference: Engineering Investigation of Window Leakage, Addendum I
 Insured: Ryland Homes Inc.
 D/L: August 1, 1989^
 Client Claim No. H61~LTT Multi Claimants
 KESCORP File No. 96340-A1

Dear Ms. Hoffpauir:

Our initial report entitled Engineering Investigation of Window Leakage, dated October 18, 1989, stated that it was unlikely that the General Aluminum Windows could pass the water resistance tests as specified by the ANSI/AAMA 101-85 DH-R25 with which they were labeled. During subsequent telephone conversations with you and with Mr. Ray Woodruff of Ryland Homes Inc. it was agreed that the windows should be tested.

Southwestern Laboratories of Ft. Worth, Texas was selected as an AAMA certified testing laboratory to conduct these tests. The windows selected for testing were all new General Aluminum Windows, taken from the Ryland Homes storage warehouse at 1310 East Richey Road, Houston, Texas. It is to be noted that these window units had never been previously installed and that they were exactly as received from the manufacturer. The window units had been stored in a vertical orientation as required by the manufacturer.

Two of the window units had been previously water sprayed at the Ryland Warehouse during our meeting of August 16, 1989 with representatives of General Aluminum. The test windows were transported from the Ryland Warehouse in a Ryland truck. Special care was taken to crate and ship the windows carefully and in a vertical orientation. The windows were protected with shipping pads as provided by the manufacturer during their shipment to the Ry' and warehouse.

The window tests were video taped for future reference. Tests conducted were as follows:

Test Window No. 1 

T-it x 3' fixed General Aluminum window with 1/2'l high lip seal and alumninum framing. The unit is equipped with nine ll"xll" single strength panes with exterior glaze, separated by vertical and horizontal mullions.

This window severely failed the initial air infiltration test by having 0.65 CFM/FT of CL (crack length), exhibit I. This leakage is 333% more than the maximum allowed leakage (0.15) for this type of window. This unit also failed the initial water'resistance test with no wind pressure applied. The window severely failed the water resistance test with only preliminary test pressure applied, 2.86 psf (pounds per square foot). 2.86 psf simulates a wind velocity of only 34 mph. The full test pressure requirement for M MA's 101-85 DH-R25 specification is 3.75 psf which simulates a wind velocity of 38 mph.

Leakage on this window occurred most profusely at the lower lip seal, photo 4. Leakage also occurred in several places at pane'glazings and at mullion joints, photos 3 and 5. Since this window failed the first three tests, we deleted the fourth and most severe test.

Test Window No. 2

A-3= x 5' single hung General Aluminum window with 1/2" high lip seal at the sill. The unit has a 35" x 30-1/4'' non-removable sash. The sash and fixed lite each have six 11"x14" panes of single strength glass separated by vertical and horizontal mullions.

This window failed the initial air infiltration test, exhibit II. It had 0.47 CFM/FT of crack length around the sash. This is 27% more leakage than the maximum allowable (0.37CFM/FT), exhibit II. The window also failed the initial water resistance test with no wind pressure applied. Water leakage through the window was significantly increased when the preliminary wind pressure (2.86 psf) was applied.

Severe leakage occurred on this unit at the bottom lip seal, at lane glazing and from water entertainment in air leakage up through the sash guides, photos 6-12. Leakage at the preliminary pressure was so profuse that we discontinued testing without running the higher wind pressure (3.75 psf).

Test Window No. 3

A 2'x 3' single hung General Aluminum window with 1" high lip seal. The General Aluminum Window was covered by an exterior storm window made by Living Windows, photos 13-15. The sash of the General Aluminum window is 23-1/4" by 18-1/4" non-removable. The sash and fixed lites each have four 10-3/4" x 7-3/4" single strength glass panes with exterior glaze separated by vertical and horizontal mullions.

This window failed the air infiltration test by having 1.04 CFM/FT of crack length, 181% more than maximum allowable leakage (0.37CFM/FT of CL), photo 16 and exhibit III. This window also failed the initial water resistance test with no wind pressure applied. Water leakage through the window occurred at an unsealed lower corner, photo 17. When the preliminary wind pressure of 2.86 psf was applied the leakage became so profuse at the final test pressure (3.75 psf) was deleted.

Test Window No. 4

A 2' x 5' single hung General Aluminum window, series 1900 with 1" high lip seal, photos 18-19 and 21. The sash is 23-1/4t' x 30-1/2" non-removable.

The sash and fixed lites have 1/2" insulated glass with exterior glaze and rigid vinyl bead. The unit has a vinyl strip in the sill and Poly pile in the exterior sides of the sash stiles.

This window failed the air infiltration test with leakage of 0.44CFM/FT of CL, photo 20 and exhibit IV. This is 19% more leakage than the maximum allowable. The window also failed severely, the initial water resistance test with no wind pressure applied. Leakage on this unit resulted primarily from an unsealed lower frame joint, photos 21-22. This window was then subjected to the water resistance test pressure of 3.75 psf, the requirement for the R-25 rating. This test failed with leakage up the sash guides and from around unsealed screws in the bottom frame, photos 23-25.

Test Window No. 5

ATIPr x 6' single hung General Aluminum window, their series 1100, with 1/2" high lip seal, photos 26-27. This window is identical to many that were installed by Ryland Homes which are the subject of this investigation. The sash is 23-1/4" x 30-1/2" non-removable. The sash contains four 11" x 131/4" single strength glass panes with exterior glaze and rigid vinyl bead. The fixed light contains six panes of the same size and glaze. The unit contains a vinyl strip in the sill and Poly pile in the exterior sides of the sash stiles. ~

This window failed the initial air infiltration test with leakage of 0.65CFM/FT of CL, exhibit V. Air leakage is 76% more than the maximum allowable. The window also failed the initial water resistance test with no air pressure applied. The window was then subjected to the full R-25 pressure rating of 3.75 psf. This test resulted in failure of the window, with profuse leakage at the glazing of panes, photo 28, water entrainment in air leakage, photo 29, flooding over the bottom lip seal, photo 30, and leakage from unsealed bottom corners of the frame, photo 31. Other views of this leakage are shown in photos 32-36.

Test Window No. 6

177FF 6, exhi377 VI, was conducted with the same 2' x 6' single hung General Aluminum window that, in test no. 5, was found to leak so badly, photos 3738. Attached to the outside of the General Aluminum window, was a storm window made by Living Windows. The purpose of this test is to determine if the addition of an exterior storm window could provide sufficient protection to the defective General Aluminum windows, to enable those windows to pass the water resistance tests for which they are labeled. (ANSI/ M MA 10185 DH-R25). .

The storm window is not designed, or intended, to be air tight or to be completely water tight. The storm windows are constructed with four weep holes in the bottom frame to drain away small quantities of water that are wind driven through the storm window. The weep holes in the storm window allow wind pressure to enter the space between the windows, thereby subjecting the protected window to some wind pressure. The amount of wind pressure that is developed in that space is dependent upon the amount of air leakage through the protected window. If the protected window had no air leakage, then the full wind pressure would be developed in the space between the windows. In that case the full wind test pressure acting on the protected window would be 0.72" of water column, sufficient to cause water to be pressured over the 1/2" high lip seal and the window would fail the water resistance test. However, the air infiltration testing of test series No. 5, shows that this window had a lot of air leakage (0.65 CFM/FT of crack length). Although this large amount of air leakage is bad as far as heating and cooling losses are concerned, the air leakage and the storm window did enable this window to pass the water resistance test in this series of tests.

Test series no. 6 shows that air leakage with the storm window in place, was 0.60 CFM/FT of CL. It is apparent from the two air infiltration tests, that the storm window has reduced the air infiltration slightly. The reduction in air leakage was also accompanied by a pressure drop across the storm window created by resistance to the air flowing through the storm window. This effectively reduced the wind pressure applied to the protected window. This lower applied wind pressure reduces the height of water column that can be developed in the lip seal of the protected window. Our initial water resistance test, conducted with no sealant between the storm window and the protected window, failed marginally, allowing a small amount of water to spill over the 1/2" high lip seal.

Since the initial test nearly passed, we determined to seal the top and two sides of the storm window in an effort to find a successful remedy for the leaking windows. Our final test set-up, with the storm window sealed to the protected window, resulted in a wind pressure between windows slightly lower than 1/2", sufficient to pass the water resistance test. [Our windows were not installed with sealant.]

Based upon the findings of this investigation the original conclusions No. 2 and 9 are hereby changed. Other conclusions have also been added. The revised list of conclusions are as restated below:

Conclusions (Addendum I):

1. The cause of window leakage in many Ryland Homes, during the storm of August 1, 1989, was numerous defects in the windows as manufactured by General Aluminum Corporation, Dallas, Texas.

2. Heavy leakage resulted from flooding over the windows inside the lip seal that is defectively undersized.

3. Heavy leakage into the walls resulted from inadequate sealant, or no sealant at all, on some of the lower corners of the window frames.

4. It is probable that many other leakage complaints have not been recognized as being caused by the unsealed window corners.

5. Leakage around window panes resulted from the  following manufacturing defects:
 

a. Bonding of the panes was defective, possibly due to delays in the manufacturing process that allowed the sealant to surface dry before contacting the glass.

b.Some window panes are undersized and some are installed in bowed-out framing, thereby lacking adequate seal contact between the glass and window frame.

c. The inner frames of the multiple pane windows are too flexible and fragile, resulting in excessive glazing stresses which are causing premature failure of the seal.

d. Inadequate attachment of the inner frame to the outer frame allows excessive deflection of the panes, producing failure of the seals.

e. Reglazing of General Aluminum's window panes requires special and unreasonable procedures, unknown by the general public and believed to be unknown by most trained reglazing craftsmen.

6. It unreasonable to require homeowners and repair personnel to be trained in special procedures for repair of window panes. 

7. It is probable that these multiple pane windows will be a continual source of major leakage for the homeowner.

8. It is recommended that the multiple pane window halves be replaced with single pane window halves to reduce the probability of leakage.

9. Testing of five different General Aluminum windows, confirms that none conform to the M MA 101-85 DH R-25 specification with which they are labeled.

10. All five General Aluminum windows failed air infiltration tests and water resistance tests as determined by an AAMA certified testing laboratory using certified test procedures as specified by ANSI/AAMA 101-85 DH R-25.

11 . Water leakage occurred at the following defects:
 

a. Incomplete seals at the lower corners of the frames that allows water to leak into the inside of walls.

b. Overflow of inadequately sized lip seal.

c. Water entrainment in excessive air leakage up the sash guides.

d.Water penetration through inadequately glazed panes.

e. Water penetration through inadequately sealed mullions.

f. Water penetration through unsealed screws in the framing.

12. The defective General Aluminum windows can, in most cases, be made to conform to water resistance testing by installation of an exterior storm window.

If you have questions regarding the above findings and conclusions, please call.

Sincerely

Weldon H. Knight, P.E.

WHK/jd