Hello everyone
I am going to cast an insulated concrete slab (9x18 meters) with water-based heating for a larger mechanic garage. To create a large and open space (that, among other things, accommodates a two-post lift with a certain lift height requirement), I will have wall and roof trusses welded in one piece with an 18-meter span. According to advice from the welder, it is sufficient to, during the casting, place iron plates with welded reinforcement wire in the bottom so that they are embedded in the slab. The plates then lie level with the concrete floor. Afterwards, the I-beams that constitute the wall elements are placed on these iron plates (with a mobile crane) and the structure is welded together. Of course, everything will be braced with cross braces and other supports.
But the question is, is this common practice?
I find it hard to believe that one would allow the walls/roof to be supported only on the slab. Shouldn't there be some heftier foundations under these iron plates? If I understand correctly, the slab should actually be insulated from the surroundings...
Does anyone know? Preferably a construction engineer. I don't have much use for guesses.
Best regards, Johan Grimm
I am going to cast an insulated concrete slab (9x18 meters) with water-based heating for a larger mechanic garage. To create a large and open space (that, among other things, accommodates a two-post lift with a certain lift height requirement), I will have wall and roof trusses welded in one piece with an 18-meter span. According to advice from the welder, it is sufficient to, during the casting, place iron plates with welded reinforcement wire in the bottom so that they are embedded in the slab. The plates then lie level with the concrete floor. Afterwards, the I-beams that constitute the wall elements are placed on these iron plates (with a mobile crane) and the structure is welded together. Of course, everything will be braced with cross braces and other supports.
But the question is, is this common practice?
I find it hard to believe that one would allow the walls/roof to be supported only on the slab. Shouldn't there be some heftier foundations under these iron plates? If I understand correctly, the slab should actually be insulated from the surroundings...
Does anyone know? Preferably a construction engineer. I don't have much use for guesses.
Best regards, Johan Grimm
Hello!
First, I want to lend some weight to my statements and inform you that I am a mechanical engineer and have worked as a concrete worker/construction worker for about 2 years. I have worked on several foundation constructions for different types of industrial halls.
It is a common solution to cast weld plates for columns and wall elements. The plates are equipped with welded reinforcement bars pointing downward into the plate. Another solution that some hall manufacturers use is to cast bolt groups that protrude from the plate, to be later screwed into the column or wall. If you cast in bolt groups, the columns must, of course, be equipped with a plate at the bottom with the correct hole pattern.
In both cases, you must have a base or foundation under the load point. Say the plate is to be 10 cm with 200 mm insulation. Where bearing walls or columns are to stand, you cut out the top insulation layer to form a beam with a 200 mm height and 100 mm insulation underneath. The beam is reinforced with several rods at the bottom and some on top of the reinforcement mat. For a column, you might make a foundation in the same way, measuring 100x100 cm. These dimensions are just examples and should, in your case, be calculated by a structural engineer. The concrete slab (for example, 100 mm thick) should not take up any major vertical loads and is really just intended as a floor. It is the bases and foundations that should support the building and heavier loads.
So the summary of this is that you can absolutely cast weld plates into the concrete slab, but make sure to have a foundation/base underneath that can handle the load. Good luck!
First, I want to lend some weight to my statements and inform you that I am a mechanical engineer and have worked as a concrete worker/construction worker for about 2 years. I have worked on several foundation constructions for different types of industrial halls.
It is a common solution to cast weld plates for columns and wall elements. The plates are equipped with welded reinforcement bars pointing downward into the plate. Another solution that some hall manufacturers use is to cast bolt groups that protrude from the plate, to be later screwed into the column or wall. If you cast in bolt groups, the columns must, of course, be equipped with a plate at the bottom with the correct hole pattern.
In both cases, you must have a base or foundation under the load point. Say the plate is to be 10 cm with 200 mm insulation. Where bearing walls or columns are to stand, you cut out the top insulation layer to form a beam with a 200 mm height and 100 mm insulation underneath. The beam is reinforced with several rods at the bottom and some on top of the reinforcement mat. For a column, you might make a foundation in the same way, measuring 100x100 cm. These dimensions are just examples and should, in your case, be calculated by a structural engineer. The concrete slab (for example, 100 mm thick) should not take up any major vertical loads and is really just intended as a floor. It is the bases and foundations that should support the building and heavier loads.
So the summary of this is that you can absolutely cast weld plates into the concrete slab, but make sure to have a foundation/base underneath that can handle the load. Good luck!
Thank you for your response!
The questions about this job continue in the post How to cast a footing before masonry?
/Best regards, Johan
The questions about this job continue in the post How to cast a footing before masonry?
/Best regards, Johan