很多老板拿着图纸去比价，回来一脸懵：两家都写“轻型钢结构”，单价能差一倍多。不是谁在乱报价，是“轻型钢结构”这个词本身就混了两套体系。

Many bosses go to compare prices with drawings, but when they come back, they look confused: both companies write 'lightweight steel structure', and the unit price can differ by more than twice. It's not anyone quoting randomly, it's the term 'lightweight steel structure' itself mixing two different systems.

先分清你到底要哪一种：

First, distinguish which one you really want:

门式刚架厂房：用热轧H型钢或焊接变截面梁柱，跨度能做到十几到三十多米，能挂5到32吨吊车，是单层车间、仓库的主流。它“轻”是指比混凝土轻、比重钢省料，不是真的薄皮。

Portal frame factory building: using hot-rolled H-beams or welded variable cross-section beams and columns, the span can reach more than ten to thirty meters, and can hang 5 to 32 ton cranes. It is the mainstream of single story workshops and warehouses. It "light" refers to being lighter than concrete and more fuel-efficient than heavy steel, not really thin skinned.

冷弯薄壁轻钢：用C型、Z型薄壁龙骨拼装，壁厚通常不超过2.5毫米，适合自建房、民宿、岗亭、临时办公楼。拿它去扛厂房吊车，半年就挠度超标。

Cold formed thin-walled light steel: assembled with C-shaped and Z-shaped thin-walled keels, with a wall thickness usually not exceeding 2.5 millimeters, suitable for self built houses, homestays, guardhouses, and temporary office buildings. Take it to carry the factory crane, and within six months, the deflection exceeded the standard.

报价差在哪儿，盯这五处就行：

Where is the price difference? Just focus on these five areas:

第一，用钢量。便宜方案用钢量压到15到20公斤每平，主梁用小号H型钢；标准厂房一般25到35公斤每平，重荷载还得往上加。每平少5公斤钢，架子就软一截。

Firstly, the amount of steel used. The cheap plan uses steel to press the weight to 15 to 20 kilograms per square meter, and uses small-sized H-beams for the main beam; A standard factory building usually weighs 25 to 35 kilograms per square meter, and the heavy load needs to be increased. 5 kilograms less steel per square meter makes the frame softer.

第二，围护板厚度。屋面墙面用0.4毫米单层彩钢，和用0.5毫米以上镀铝锌板加岩棉夹芯，每平差出几十块，但后者保温、防火、抗风差着一档。

Secondly, the thickness of the enclosure board. The roof and walls are made of 0.4mm single-layer color steel, and coated with 0.5mm or more aluminum zinc plate and rock wool sandwich, with dozens of pieces per adjustment. However, the insulation, fire resistance, and wind resistance of the latter are inferior.

第三，基础与预埋。铰接柱脚、简单独立基础最省；刚接柱脚、锚栓精度±2毫米、地基承载力按150千帕以上算，这部分省了，后期柱子歪、墙板裂。

Thirdly, foundation and pre embedding. Articulated column base and simple independent foundation are the most economical; Just connect the column base, anchor bolt accuracy is ± 2 millimeters, and the foundation bearing capacity is calculated based on 150 kPa or above, which saves some time. Later, the column will tilt and the wall panel will crack.

第四，防腐防火。济南春夏潮、冬季化雪盐雾重，构件至少喷砂到Sa2.5级，再上环氧富锌底漆；防火按耐火等级刷对应涂料。裸钢直接拼装的低价单，三五年就开始返锈。

Fourth, anti-corrosion and fire prevention. Jinan spring and summer tide, winter snow and salt spray heavy, components should be sandblasted to at least Sa2.5 level, and then coated with epoxy zinc rich primer; Apply corresponding coatings according to the fire resistance rating for fire prevention. Low price orders assembled directly from bare steel begin to rust within three to five years.

第五，报价含什么。很多600元的“全包价”其实只含钢骨架，基础、地坪、门窗、防火涂料全另算。签合同前让对方拆成“主体/围护/基础/防火”四行写，裸价和全包价一比就露馅。

Fifth, what is included in the quotation. Many of the 600 yuan "all inclusive prices" actually only include the steel frame, and the foundation, floor, doors and windows, and fireproof coating are all calculated separately. Before signing the contract, ask the other party to split it into four lines: "main body/enclosure/foundation/fire prevention", and compare the bare price with the full package price to reveal the truth.

再补两条现场红线：

Add two more on-site red lines:

柱距别盲目拉到9米以上，有吊车或雪载大的地区压到6到7.5米，梁截面反而更省。

Do not blindly increase the column spacing to more than 9 meters. In areas with cranes or heavy snow loads, press it to 6 to 7.5 meters, which will actually save the beam section.

支撑系统不能省。很多“轻钢便宜方案”把柱间支撑、隅撑砍掉，风一吹整体侧移超标，刚架没坏、房子先晃散。

The support system cannot be saved. Many "cheap light steel solutions" cut off the support between columns and corner braces, causing the overall lateral displacement to exceed the standard when the wind blows, and the rigid frame is not damaged, causing the house to shake apart first.

把“体系先定对、用钢量写进合同、围护和防火单列、基础精度现场验”这四句钉在发包单上，同样一栋车间，全周期能少花几万还能过验收。

Nail the four sentences of "system first, steel quantity written in the contract, enclosure and fire protection listed separately, and foundation accuracy on-site inspection" onto the contract, and the same workshop can save tens of thousands of yuan and pass the acceptance inspection throughout the entire cycle.