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Damage by Electrical Contractors
5

Damage by Electrical Contractors

Damage by Electrical Contractors

(OP)
The picture below is a recent repair job that I worked on. Single story commercial building in a 155 mph (ult) wind zone. Over 60% of the gable end wall was compromised. The fix was both presciptive and engineered. Any thoughts on what you might do?



I guess this is a good example of "What not to do as an electrician" or any other trades person for that matter.

RE: Damage by Electrical Contractors

Yikes. I assume shear controlled the strength at these swiss cheese studs? I'd probably notch out a 2x6 and sister it to the existing stud and carry it up the wall enough to grab half the shear in the existing stud. Should replace enough of the cross-section for shear and axial loads.

Maine EIT, Civil/Structural.

RE: Damage by Electrical Contractors

Maybe sister on a small steel angle somehow at each one and delvelop into the stud above.

RE: Damage by Electrical Contractors

(OP)
Notice how close the slot is to the sill plate in a couple of studs. A strap fix in my opinion could not develop enough strength below the slot. Also the amount of wood left towards the exterior side on a couple of the studs (not visible) was less than 1". My worry there was that the bending forces on the studs from the wind would put these specific areas in considerable compression. A strap on the outside would be great for nail protection for the wires and tension but do nothing for compression due to bending. Part of the fix was to sister 2x4s (flatwise) onto the 2x6 studs against the ext. walls in these areas.

RE: Damage by Electrical Contractors

Nail a full height 2X6 to the inside edge of the wall, transverse to each of the studs. Nail off top and bottom with framing clips and 12d @ 6" staggered at the "L" intersection of the studs. Also glue the stud edges together. Should be better than the original.

Mike McCann, PE, SE (WA)


RE: Damage by Electrical Contractors

The electrical conduits were always going to take some space. Looks like that space will now be taken by additional studs placed to the inside of the conduits.

RE: Damage by Electrical Contractors

If it's bending or any type of compression failure, you might make something work by adding extra sheeting. That won't really help you if you have a problem with shear perpendicular to the wall, though.

RE: Damage by Electrical Contractors

(OP)
Basically that is what we did but with 2x4s, and then as an added measure we had them sheet the interior wall with OSB. The wall is now stronger than the original.

RE: Damage by Electrical Contractors

Who pays for the design work?

RE: Damage by Electrical Contractors

Just schlep on several layers of fiberglass like they're doing to repair concrete garages.

RE: Damage by Electrical Contractors

How long is the wall? (How much further (to the left) does the damage run?)

RE: Damage by Electrical Contractors

(OP)
One more stud bay to the left and two more stud bays to the right.

RE: Damage by Electrical Contractors

have the electrician reroute conduits to attic or lower level and feed into wall at DCO and switch locations. Then replace or add on studs.

just a thought.

RE: Damage by Electrical Contractors

What did the architect have planned for this detail?
What did the PE who signed off think was going to happen?

Not that I'm all that happy with a certain type of get-it-done tradesmen. The ones who no matter what job they have to do create far more damage to the surroundings than justifies anything they were supposed to do.

Take down a tree? Sure. Lawn destroyed with skid-steer for free.
Replace a clutch? Sure. Body destroyed at bad lift location.
Fix some plumbing? Sure. Slop in some concrete to patch the floor.

RE: Damage by Electrical Contractors

This is fairly typical, architect draws up a 4 pound box, MEP engineer designs 8 pounds of equipment...contractor is supposed to magically make it work.

I can envision the RFIs now....

Electrical Contractor - "wall is not large enough to run all required circuits, please provide chase."
Architect - "Chase is not permitted ,room is at ADA minimums"
Electrical Contractor - "Submitting extra for additional wire needed to go around wall"
Architect - Reject extra..
Electrical Contractor - gets out the drill...

RE: Damage by Electrical Contractors

Run a vertical 2x4 between the holes (slots) and the face of the existing 2x4, the second 2x4 in each 16 inch interval to be at right angles to the first 9original) 2x4; and the second 2x4 to be nailed to the first so they make an "L" that fits between the floor baseboard and the upper (usually 8 ft) 2x4 header.

That will resist the vertical loads, and the twisting loads as well.

RE: Damage by Electrical Contractors

Next time, use 2X4 HSS members for the studs. It should prove interesting... 2thumbsup

Mike McCann, PE, SE (WA)


RE: Damage by Electrical Contractors

Have the electrical contractor stand there and hold up the wall for the life of the building.

Problem solved.

RE: Damage by Electrical Contractors

(OP)

RE: Damage by Electrical Contractors

(OP)


RE: Damage by Electrical Contractors

The newest pictures seem to reinforce that the problem didn't lie with the contractor, but with the MEP engineer, and his lack of communication with the architect.

It's poor engineering, to stick your head in the sand and issue out drawings you know cannot be built,or maybe it's worse, when you really have no idea if it can be built.

This is a fairly small project, but these problems tend to scale up with the size of a building ,at which point ,it's next to impossible to get direction on how to proceed with a fix ,to such a poor design. The endless stream of RFIs that get shuffled from one office to another, with no one willing to admit culpability. " Have the electrical contractor stand there and hold up the wall for the life of the building." Typical... "have the contractor pay for my piss-poor design...he should've seen this at bid. I spent 6 months designing the thing, hell, he's got two weeks to put a price together, and find all my mistakes".

I just reviewed a set of plans, quarter billion dollar range. There must be at least 18 months and a few hundred thousand spent to get to this bid set.15 minutes into the drawings. Hey, the column enclosures are so tight, the specified fireproofing won't fit behind the drywall, let alone the piping that is shown in there too. Call the MEP engineer ..."well, the architect has my revit file"...Call the architect....."Submit RFI's on a case by case basis"....So now the contractor has to spend his resources to get the engineer and architect to communicate with each other. Whatever happened to the AIA guidelines.

Put out an incomplete design and call it coordination for the contractors.

RE: Damage by Electrical Contractors

Looks familiar.

Install a flat 2x4 on each side of the 2x6. 90 degrees to the stud.

RE: Damage by Electrical Contractors

hvacpiper, I don't know what it is nowadays, but these type of problems are too common. I bet all of the units are independently metered with one service room. This was an obvious problem from day one. Some of the architects I deal with today seem to be more like cake decorators, rather than what their job is intended to be. I suppose you are correct that it should be the MEP eng that speaks up and suggests there is a problem, but an experienced architect should anticipate this type of problem and build a sacrificial service wall if they cannot live with surface mounted conduit. One Architect we work with can tell me everything about his silly furniture (one floor plan dwg file was 15Mb), yet, his understanding of how things goes together is very very poor. I get why, their clients are most interested in talking about those features. They seem to forget their clients unspoken interest in avoiding field problems.

So why is it the architects still get paid magnitudes more than the engineers that figure out the nuts and bolts? hmm, I think we engineers need to work on our branding. :)

RE: Damage by Electrical Contractors

This a good object lesson for the younger engineers out there. Just because you're a structural engineer doesn't mean you don't need to be aware of what the other trades need to do.

We had a long skinny two story school building with the electrical and IT rooms on one end. Contractor elected (no guidance on the drawings) to run 40 conduits under the slab and then up the nearest interior transverse shear wall. The sill plates and double top plates looked worse that this picture because he spaced the damned things out, thinking that was better. The holes in the sill plate were large just to make sure they fit over the electrical stubs coming through the footing. Of course the sill plate split and don't even think about having effective end distance on the sill bolts. Oh, did i mention it was supposed to be a double sheathed shear wall. Now I insist on a seperate electrical chase on the structural drawings and make sure the architect does the same.

Plumbing and mechanical can do similar things. Make sure you see the ducting drawings before plan check.

Mistakes/screw-ups are the worst/best teachers. Murphy's law - If it can happen, it will.

LonnieP

RE: Damage by Electrical Contractors

(OP)
I agree with you Brad805 we don't get paid enough or seem to get as much respect as the architects.

I was going to work for a company about a year ago that designed timber trusses for high end homes and commercial projects, mostly what they were going to hire me for was my artistic/design ability. However, I also mentioned that I was a licensed PE and that as an added bonus I could also do the structural analysis of the trusses and eventually write some software that would automate this process for them for the most common truss types.

Their response was, "We're not really concerned with the engineering of our timber trusses, we just need them to look nice. We can pay any engineer a couple hundred bucks to make sure they actually work". I was a little surprised at the lack of respect towards the engineering discipline, needless to say I did not end up working for these guys.

RE: Damage by Electrical Contractors

The thing about this is, it isn't possible for the Structural to know it is coming. Have had a few podium slab projects with (3) stories of wood on top. I knew there would be punching shear issues with all the conduits at the electrical room so I asked the MEP engineer for conduit size/number/layout. His response, "I cannot give you that, it isn't in my scope". The MEP engineer simply doesn't care in many (most in my experiences)instances when dealing with residential of any size.

RE: Damage by Electrical Contractors

There's no way any party can foresee every issue that may pop up in a building design.

That being said, it sure seems like building design has taken on a much more linear progression lately... Architect-> Structural-> MEP -> Out to bid. Without cycling the design through the chain once or twice, these conflicts are bound to be there.I think it's unfair to dump all the responsibility on the contractor. They just do what the drawings tell them to..

RE: Damage by Electrical Contractors

Architects = Cake Decorators

Star for you!

RE: Damage by Electrical Contractors

We have collectively entered a very interesting profession. I suppose it has always been us against the contractors, but that is not correct in my view. Our ultimate goal should be to achieve our clients project goal. When we were working for architects the mindset used to be 90% of our job virtually complete once our deliverables were handed over.

Our company does the engineering for a precast concrete company now and I see consultant drawings from all over the province. Some of them I look at and wonder in dismay how they expect the contractor to complete the project. One project that was tendered in our area years ago mimicked the shape of an eagle. There were endless curves in the project. The architectural drawings had some limited dimensions on the plans and a ton of generic details that they expected the contractor to interpret and figure out the appropriate material quantities for bidding. The engineers drawings only had gridline dimensions and some key dimensions in the sections. How that design team hoped to avoid endless RFI's was beyond me. It came in way over budget and was re-designed....shocking.

The question that puzzles me, is how can we fix it? Projects are getting more and more complex and the bottom line is more and more important for growing companies. The other reality is extra's are big business for many contractors. I know of contractors that have a senior staff member that go thru bid documents to find all of the loop holes and reduce their price knowing full well they will charge an inflated extra later. Some may say BIM will solve this, and it can to a degree, but I see many are using this largely as a dog and pony show. This is not always helpful. There are endless ways to add generic details with BIM if you are working with traditional firms that have specific 2D detailing teams. Another question I wonder about is how do we get our clients to go thru the boring, but important questions during the design process? Increasing fees to allow for additional review time might help, but many firms simply do not have the staff that can find these type of problems. Our insurance company has reported that the most common cause of fault in claims has been traced back to under qualified staff in most cases. Then there is the inevitable problem convincing an owner they should pay more. Many owners do not appreciate the complexity of a building project, and it is difficult to convince them of the importance of these type of questions until we end up debating the "who pays" question. We have not worked for an architect in years, and work mainly for design/build contractors that we have cherry picked. Even though they are the builders I still struggle at times to get them to want to look thru documents and try to anticipate problems. I have elected to ask them endless questions one by one. Not too many questions at once or you will not get an appropriate level of review. The problem with this method is it is tedious and only works for projects up to about $15mil in value.

medeek, I understand your truss interest more now. I recall talking with a truss engineer years ago. He was paid $75 to seal each truss sheet. On the topic of owner interest, our insurer polled owners and engineers separately on the most important aspects of any building project they undertook. I forget all of the questions, but what did stick in my mind was how dissimilar the owners interests were compared to the engineers. I seem to recall almost 90% of the owners put cost and on-time first. I suspect most of those owners simply assume that engineers cannot make mistakes or would ever miss something.

RE: Damage by Electrical Contractors

The differences between the USA and the UK/Europe are endlessly interesting to me. What sort of building is this and what is it used for. What would be the external cladding and what are the walls covered with on the inside. A small industrial unit where I live in England would usually be a portal framed steel construction clad with twin wall foam insulated plastic coated profiled steel sheeting. The dwarf walls below the cladding would usually be concrete blocks or maybe brick. There are very few wooden buildings and when it is used it is usually clad with brick. Most domestic housing is brick built.

RE: Damage by Electrical Contractors

Wooden houses (singe-family size) tend to be more and more a wooden frame with only a brick facade (non-load bearing). (I'm talking Belgium here)
Mostly for passive or low footprint reasons: they are much more thermally isolated than classis (= brick) houses.

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