Inspection Methods for Prefabricated Houses

The inspection methods for prefabricated houses mainly include the following:

Observing the floor slab structure is a relatively intuitive method. Prefabricated slabs usually appear as regular blocks with obvious gaps between them, while cast-in-place slabs have a flat surface without noticeable splicing marks. By observing the appearance of the floor slab, one can initially determine its structural type.

Checking the construction year can also provide clues. Houses built earlier often use prefabricated slab structures, while those built in recent years generally adopt cast-in-place concrete structures. Understanding the construction time of the house helps narrow down the scope of judgment.

Tapping on the floor slab to listen to the sound is a simple and effective inspection method. Gently tap the floor slab with a hard object. The sound of a prefabricated slab is crisp and has a long echo, while that of a cast-in-place slab is dull. The sound differences produced by different structural types are significant and can be used for differentiation.

Examining the design drawings is the most direct and accurate method. If there are design drawings of the house, checking the structural type of the floor slab can clearly determine whether it is a prefabricated slab. However, this method is limited by the availability of the drawings.

Observing the areas where pipes are laid also has a certain effect. The presence of columns or reserved holes may indicate a prefabricated slab, while the absence suggests a cast-in-place slab. However, this method needs to be combined with other inspection methods for comprehensive judgment, as its accuracy is limited when used alone.

Observing the interior walls of the house can assist in judgment. If there are no beams on the walls and no columns at the intersections of walls, it indicates a prefabricated slab; conversely, if there are beams above the walls and columns at the intersections, it is a cast-in-place slab.

Drilling holes in the floor slab can provide direct verification. During the production of prefabricated slabs, holes with a diameter of about 8 centimeters are usually made every 3 centimeters. If a hole is drilled and an empty space is encountered, it indicates a prefabricated slab. However, this method can cause damage to the floor slab and should be used with caution.

Checking the conventional physical parameters of the floor slab can further confirm. Lift the baseboard to check the edge thickness of the slab. The actual thickness of a prefabricated standardized product should be 16 ± 2 centimeters, and the hole spacing should be in an arithmetic sequence of 12 - 18 centimeters.

Using professional inspection tools yields accurate and reliable results. Hire a construction engineer to use ground-penetrating radar to scan the house frame and distinguish the ripple differences between the steel reinforcement mesh in the cast-in-place structure and the preset metal joints of the prefabricated slabs.

Verifying through ground micro-vibration feedback is also a method. After turning off the air conditioner power in the room, have two people alternately jump at different points to trigger low-frequency vibrations. A room with prefabricated slabs will produce continuous amplitude aftershocks.