摘要：灰缝是砌体的最弱环节。讲灰缝厚度标准、错缝原则、泥浆饱满度检查三个控制点。
Abstract: Joints are the weakest link of any lining. Three controls: joint thickness, staggered bonding, and mortar fill inspection.
正文： 炉衬出问题，十有八九先坏在灰缝。砖再好，缝没砌对，气体钻、渣子啃，寿命照样打折。
Main text: Most lining failures start at the joints. Good bricks, bad joints: gas finds its way, slag gnaws, and life drops anyway.
一、厚度两到三毫米
1. Two to three millimetres
炉墙灰缝控制在2至3毫米，拱顶更薄。缝厚了受热收缩开裂，缝薄了泥浆不饱满，两头都不行。
Keep wall joints at 2–3 mm, thinner on arches. Thick joints crack on heating; thin ones leave voids. Both fail.
二、错缝是铁规矩
2. Staggering is iron rule
上下层竖缝错开四分之一砖长以上，转角咬砌。通缝等于给裂纹修了条直路。
Offset vertical joints by a quarter brick minimum, interlock corners. A straight seam is a highway for cracks.
三、饱满度用网板查
3. Check fill with a grid
百格网抽查泥浆饱满度，达标率90%起。膨胀缝里掉进泥浆，等于缝白留。
Spot-check mortar fill with a grid plate; ninety percent is the floor. Mortar dropped into an expansion joint cancels the joint.
- 先看缝再验砖，缝比砖更容易出事。
Inspect joints before praising bricks; joints fail first. - 灰缝验收要趁砌筑时做，砌完再查只能返工。
Joint inspection belongs during masonry, not after. - 膨胀缝干净，比灰缝饱满更容易被忽视。
Clean expansion joints get forgotten even more than full mortar joints.
砌筑这活考验的是耐心，缝缝计较，炉衬才给面子。
Masonry rewards patience. Fight for every joint, and the lining pays you back.
