Home page FOR ESTIMATE CALL:1-818-273-9980



Structural Strategy – (001): Cost Reduction EM1



To reduce the cost of construction; followings are some items to remember when designing a wood structure:


1.       Minimum shear wall width should be ½ the shear wall height, or consider using Simpson Strong Wall or steel frames which are more expensive.

2.       2nd floor shear walls that do not have shear walls below, and sit on a floor beams, the floor beams should be designed with over-strength factor Ω=2.5 times the seismic loads. Therefore, making the beams and associated posts and footings much larger.

3.       For Flag Pole Design, response modification factor R= 1.5 V.S. Shear walls who's R=6.5, therefore we must design the flag pole 6.5/1.5=4.33 times the associated seismic loads.



Structural Strategy – (002): Site Observations EM2



After numerous site observations, followings are some items to remember when designing a wood structure or doing any additions to existing houses:


1.       When designing planters around the exterior of the building and close to foundation, be sure to waterproof the planter walls either above or below the grade and have proper weep holes and the piping to take the water away from the building foundations. We have noticed lots of times those planters which do not have waterproofing and they have been built against the foundations, the water tends to seep below the foundation and sometimes into crawl space and soak the individual pier footings. This in turn causes either exterior footing settlement or settlement of an individual pier which is the cause of many floor unevenness and warping.

2.       Also, for new or addition to existing dwelling, be sure that down spots from the roof drainage are properly piped away from the base of footings or planters around the building. In our observations, we have noticed that the existing down spots are right at foundation stem wall or at planters around the exterior of the buildings which causes of footing settlement and seepage of the water in to crawlspace. Therefore, it would be a good idea to recommend getting the water away from the base of the footing at least for few feet by use of some piping, although it is not required by the code for existing structures.

3.       Try to provide minimum 3 feet a concrete slab apron with the proper slope away from the foundation walls around the building wherever possible.



Structural Strategy – (003): Major Remodeling of Existing Houses EM3



In major remodeling and alteration of existing houses, advice the owners to consider the following items which will both enhance the structural capacity and the energy conservation of the existing houses; saving the owners energy bills, repairs and peace of mind in future.


1.       Remove drywall from all exterior walls

2.       Repair and replace all damaged, specially termite damaged studs, posts and beams

3.       Install new insulation (R-13)

4.       Do new wiring and install additional outlets

5.       Change old plumbing pipes to copper plumbing

6.       Possibly, add plywood shear walls and hold down where there are too many windows in the same wall

7.       Check for floor unevenness, bumps, slopes. Check the pier foundation. This is a good time to repair and replaces the damaged piers and even out the floors.

8.       To do rebolting and reinforcing of the existing foundation

9.       Get a structural engineer to do a structural inspection and to recommend on framing repair, shear walls, rebolting and foundation repairs



Structural Strategy – (004): As-Builts EM4



As we all know, As-Built plans are a vital and essential part of our design industry. To reduce the cost of building design and construction, it helps to have well drawn-out and analyzed Architectural and Structural As-Built plans.


Architects analyze a building in a designer’s perspective.  They get a good architectural As-Built plan of the existing building, but they generally overlook the structural components necessary for the structural design of the building.


Therefore, we suggest:

1.       Architects when hiring structural engineers, ask them to include in their fees, either a job site visit, or to obtain partial As-Built plans along with a photographic survey of the structural components, as much as possible.

2.       Structural engineers could also be hired just to provide full structural As-Built plans to help drive the design charrette stage of the job and the final architectural and structural drawings.

3.       Not knowing existing conditions and/or lack of information in the As-Built plans can trigger the engineer to overdesign.

4.       By knowing the existing structural component, architects and engineers may modify their design approach to implement and integrate the existing structural components such as; use of existing pads and continues footings, basement walls, posts and girders. By doing so, the cost and time of design and construction is greatly reduced.



Structural Strategy – (005): Solar Panels EM5


SOLAR PANELS (attn: Architects & Engineers) 

Nowadays, the use of Solar Panels to produce electricity at home is very popular, due to its cost saving in the future. As Architects and Engineers, when clients ask us about the installation of the Solar Panels we should be very careful in advising them.

Things to consider:

1.       The weights of solar panels? (Usually 3-5 PSF?), proper connection of it to roof members.

2.       Is roof framing: Ridge Beams, and ridge boards, rafter bracing, the span of the rafters and the size of the rafters capable of carrying the panel loads..

3.       Is roof properly connected to wall? Is any of the solar panel loads concentrated on an existing beams or headers?

4.       What is the lateral implication of the panel weight spread on large area? Are existing shear walls having sufficient capacity to carry the loads?

5.       Is foundation sill plate bolted? Is the foundation okay to carry the panels additional loads?

Due to above consideration , it is good advice to ask clients, or the company installing the Solar Panels, to consult Architects or Structural Engineers to evaluate the exact roof and building framing condition. By knowing the existing structural component, architects and engineers may modify their design approach to implement and integrate the solar panel location on the existing structural components such as roof rafters, posts, girders, pads, and continues footings.



Structural Strategy – (006): Solar Panels EM6


SOLAR PANELS (attn: Contractors) 

Nowadays, the use of Solar Panels to produce electricity at home is very popular, due to its cost saving in the future. As Contractors, in the installation of the Solar Panels DID YOU KNOW?...................

1.       Did you know that by installing of Solar panels on damaged or decade rafter you may break the rafter?

2.       Did you know that additional weight of Solar Panels may exasperate the condition of a flat roof with pounding issues?

3.       Did you know that with inadequate rafter ties you may damage the roof and wall connection?

4.       Did you know that by installing Solar Panels on rafters which are carrying HVAS loads in the attic you may damage it?

5.       Did you know that the concentration of many rows of the Solar Panels on a long window header on a single rafter may damage the header or rafter? Also, it may hinder the window or door operation?

6.       Did you know that the concentration of solar Panels on a portion of the roof of a building without adequate shear panels may damage the building considerably at the time of earthquakes?

7.       Did you know that old roofs may have two layers of roofing, therefore; installing Solar Panels will further reduce the capacity of existing rafters and rafter ties.

Therefore, a thorough evaluation of existing roof framing by a licensed Structural Engineer is essential to insure your company's excellent reputation from mishaps and costly legal procedures.

Copyright © 2012 www.oksn-associates.com, All Rights Reserved.