Old building additional floor renovation design and construction light steel house building

For adding floors and expanding rural old houses, as well as renovating and transforming villas, many brick-concrete structures cannot address the load-bearing issues. Using a light steel system offers structural stability, ease of construction management, high construction efficiency, short construction periods, small cross-sectional area, and light self-weight, providing more usable space compared to equivalent reinforced concrete structures. Therefore, the light steel structural system is highly advantageous in floor addition and expansion projects. #HouseRenovation #OldHouseTransformation

Light Steel Villa vs. Brick-Concrete Villa

First, let's discuss the differences in structural materials between light steel villas and brick-concrete villas:

The light steel structure is made of G550 high-strength aluminum-zinc alloy, offering superior rust and corrosion resistance. The aluminum-zinc coating is 150 grams per square meter. The national standard for galvanized steel materials is 60 grams per square meter, while the galvanized coating on outdoor high-voltage transmission towers is 160 grams per square meter (ensuring no rust for 50 years in exposed environments). Light steel materials adhere to the American G90 standard, with a galvanized coating of 275 grams per square meter. Aluminum-zinc coating provides 3 to 6 times the corrosion resistance of galvanized coatings. Therefore, 150 grams per square meter of aluminum-zinc coating is equivalent to 450 grams per square meter of galvanized coating. Light steel materials enclosed within walls are even less prone to corrosion and can last 100 years without rust (data from the Ministry of Housing and Urban-Rural Development).

Brick-concrete structures, on the other hand, combine traditional bricks, cement, sand, and steel reinforcement. With proper maintenance, the lifespan of concrete can reach 50-60 years. However, due to the inherent expansion and destructive effects of concrete, if no measures are taken, its lifespan may be shortened. The design service life of brick-concrete structures is 50 years, but this does not mean the building is uninhabitable after 50 years. Instead, the safety factor decreases, requiring building assessment, repair, or reinforcement.

2. Design: Light steel structures are custom-designed by architects based on standard drawings, allowing for complex structural designs without additional costs.

Brick-concrete structures generally lack standard drawings, with workers making adjustments based on experience during construction. Simple designs are common, while complex designs require higher craftsmanship, significantly increasing costs.

3. Cost: Light steel villas are calculated based on the projection area, with the roof area not separately calculated. The rough construction includes water and electricity, doors and windows, and exterior wall and roof decoration.

For brick-concrete villas, cast-in-place roofs are calculated separately at 50% of the area. The rough construction does not include water and electricity, doors and windows, or exterior wall and roof decoration.

4. Safety: Light steel structures bear loads as a whole, with mutual reinforcement and strong resistance to deformation and recovery. They can withstand magnitude 9 earthquakes and category 13 typhoons, making them the primary building structure in earthquake-prone areas. Under rare seismic events, the main structure remains intact and does not collapse.

Brick-concrete structures have an earthquake resistance rating of magnitude 5-6. Earthquakes exceeding magnitude 6 pose risks. While concrete and bricks appear solid, collapse can occur instantly, causing severe harm. We should consider how many rural brick-concrete houses lack proper supervision and fail to meet standards.

5. Insulation: Light steel villas are equipped with insulation systems. With the same insulation effect, 5 cm of polyurethane or 9 cm of insulation wool can match the insulation of 76 cm of concrete or 1.7 meters of brick walls.

Brick-concrete villas generally lack professional insulation systems, as cement and bricks have poor insulation properties.

6. Speed: The main construction period for light steel villas is 25-30 days, with dry construction unaffected by weather conditions.

The main construction period for brick-concrete villas is 3-6 months, with construction affected by weather.

7. Environmental Impact: Light steel villas are 90% recyclable, generate minimal waste, and cause no pollution during construction. They are prefabricated buildings strongly promoted by the state.

Traditional brick-concrete villa materials are not recyclable, generate large amounts of waste, and cause significant environmental pollution. Currently, some materials used in brick-concrete construction are subject to various restrictions by local governments. As traditional brick-concrete construction masons become increasingly scarce, craftsmanship relies solely on accumulated construction experience. Over the decades, there has been little fundamental progress in this field. Skilled craftsmen are dwindling, and young people are unwilling to work on construction sites, leading to a situation where older workers are more valued. The future development of prefabricated buildings will transform migrant workers into industrial workers, eliminating the need for construction experience. With simple training, they can assemble structures according to drawings, giving them a sense of belonging, achievement, and promising career development. Only in this way can the supply and demand situation in construction labor be reversed.