Commercial Steel Estimating. Kerri OlsenЧитать онлайн книгу.
Steel Detailing
Steel detailing is the very complicated and exact process of extracting all the steel items shown at the contract drawings, then accurately drawing or “detailing” these steel items to be shop fabricated in such a way as to be easily understood. Steel detailers will create shop fabrication drawings from the very contract drawings with which you are creating your quote.
The contract drawings show the steel support framing of the building as the finished product. The shop fabrication drawings will show the very detailed and specific information required to allow the steel shop welders to actually make all those parts and pieces intended for the framework. The steel detailers provide the steel erection drawings that locate each and every part used in the framing, including all of the miscellaneous steel fabricated items.
There are industry standards for the steel detailing process that we will not address in this book. As you are building your library of publications that are part of your trade, it is a good idea to get a copy of a steel detailing manual (see notes and references) to study and reference. This will not only help you to understand more of the specifics of what steel detailers do, but will also help you learn to read shop drawings if you are not already familiar with them.
It is important to understand that steel detailers take the estimated work to a finished product level. Steel estimators can get away with a plus or minus in inches or even feet in doing the “take off” or material listing, but steel detailers must be accurate to the nut with what they do. Every part and piece that they draw must be such that the steel will fit up in the field 100%. If the steel does not fit as it should, it will cost the fabricator (as well as the general contractor and all the other trade work that follows the steel) much in the way of time and money.
The steel detail drawings are typically a buyout item for most fabricators. Some steel fabricators do have in-house detailers, although the practice is not as common as it once was. Contract drawings used for bidding tend to be ambiguous in many areas. It is the steel detailer’s job, together with the project manager and the steel estimator, to iron out all the issues as they move along with the drawings. Good project managers along with the steel detailers will perform an initial review of the contract drawings to identify early on some of the project’s most glaring issues.
Requests for Information (better known as RFIs) are sent to customers to cover any questions that the steel detailers have regarding the job. The project manager is responsible for tracking them and making sure that the questions are answered in a timely way so that the steel detailers can continue with their work.
Creating and submitting RFIs is the job of the project manager and the steel detailer together. Steel estimators need to understand this process because they are the first to see these issues while creating the quote for a project. The need for RFIs becomes apparent to steel estimators during the take-off process.
Details will be found that don’t look right, or are missing in relationship to the information that is shown in the drawing’s plan views. This book includes sample conditions for possible RFIs within Chapters 7, 8, and 9. These sample conditions help estimators begin to understand what to look for.
Once you have decided to quote a specific project, it is best to alert your chosen steel detailers early on of your intent to quote. Ask them to provide you with pricing to prepare the shop detail drawings on the job. By contacting them early, you enable them to get your bid request in line with their own work load. They are more likely to get a price to you in a timely manner. Giving them a copy of your bid letter as a guide will help them create a quote more quickly. If you have any break out items in your final bid, be sure to let your detailer know so that they will break out their pricing accordingly.
Labor Hours
Labor hours reflect the amount of estimated time for the shop to fabricate the steel for the entire job. This labor time can be added to your quote items in several different ways—it should be specific to the way your shop needs the labor applied. Some shops labor every item individually; others labor in groups. In some cases, the individual part cuts, miters, cut to shape plates, holes, and welds might be timed, whereas others simply indicate a certain number of hours or minutes per types of parts.
However the individual labor times are applied, the total hours are reflected in this line item. The cost per labor hour will vary from shop to shop, by region, and by project requirements (prevailing wage, Davis Bacon wage rates, or others). The cost per hour is installed next to the labor hours for that extended pricing.
Materials
Materials will be the total cost of steel on the job. This cost should be the actual purchase amount of the steel that is needed to build the project, including waste. Material purchases will be based on available lengths from either the warehouse or the mill.
Material suppliers often have steel reference guides they provide for their customers to use. These reference guides provide specific data including material weights and stock lengths, designed to assist their customers with making a purchase.
Hardware
The hardware slot is where you enter all your bolts, nuts, and washers. Having this category itemized at the bid stage makes budgeting easier after you get the job; you will already be aware of how much of your budget is for hardware without having to go back and break that out.
For the hardware line item, we generally consider bolts for the steel fabricator’s work only. Therefore, we include here anchor bolts for columns and embeds, steel-to-steel bolts for columns to beams, and beam-to-beam connections.
Buyouts
Buyouts can include grating, expanded metals, and railing brackets—anything that is necessary to complete the fabrication of the project. Some companies may require further breakdown of these items individually. If so, just make another line item for each one.
Large buyouts, like steel grating or heavy plate cutting, may be listed separately, including the weight of the item. This breakout will make it easier for other departments to see the applied budget. Supportive notes regarding lead time in scheduling and the timing of the financial commitments are helpful.
Paint
Because many shops do their own prime painting, it is good to have the cost of paint materials broken out for budgeting. This category is where you enter your estimated paint material cost. The company may also require costs for expendables associated with the paint, like cleaners, filters, or small tools (e.g., grinding wheels). Such expendable costs might be reduced to an average percentage for amortization purposes; this percentage would then be added to the actual cost of the paint.
Paint Labor
Structural and miscellaneous steels are generally prime painted unless shown as fireproofed or galvanized. Some shops do their own prime and finish painting; others ship the steel to a shop that will paint for them. This category is the place to enter either the labor hours to paint the coating or the cost of a supplier to perform that service. If painting is outsourced, costs may also have to be added at the line item for shipping and handling.
Galvanizing
Galvanizing is a buyout item that is often utilized for steel fabrications that will be exposed to extreme weather or caustic conditions. These items are broken out by weight, plus the additional (average) 10% weight factor for the galvanizing itself in order to get accurate pricing. Some shops consider galvanizing and some don’t. Be certain. Ask if the 10% (or other factor) needs to be added to the base weight to verify that the correct pricing is being generated.
Galvanizing pricing is particular to the types of fabrications requiring galvanizing; therefore, a galvanizing shop will need to be contacted to get this information. A list of items needing to be galvanized, along with the weight and size for them, will need to be compiled to obtain