Stiffening ribs for a stud wall
Feb 25, 2009 3:53:42 GMT -7
Post by chrisbee on Feb 25, 2009 3:53:42 GMT -7
While responding to another thread I may have visualised a useful, lightweight, clean and fairly inexpensive way of seriously stiffening a stud wall for a vertical array.
Girder bridges have been around for quite a while. They rely on great depth in the side girders to resist the applied vertical loads loads on the roadway between the built up side panels. They take heavy and widely varying loads and absorb lots of serious vibration. Deep vertical side ribs and cross bracing shelves should do the same job in an IB baffle wall housing a vertical array.
Glue-lam and built up joists function well in many buildings. The depth of the joist is where the strength lies. This can be imitated for our IB purposes with deep plywood ribs set on edge to the applied loads and well attached to the existing vertical wall studs. The baffle will close the box at the front becoming the deck in our vertical IB "bridge". Stiffening shelves between the ribs will resist any twisting of the vertical ribs themselves under heavy reaction loads.
The ribs ought to be at least a foot deep from front to back and the full height of the room. The ribs must be well attached to the vertical wall studs, the floor (and hopefully) the ceiling.
I could even imagine an entire wall between two habitable rooms being stiffened with these deep ribs and the cross brace shelves being utilised for open storage. MDF might be just as useful as plywood in this context depending on the cost of each material locally.
Wide decorative chipboard and MDF shelves are readily available and could be utilised for the ribs and shelves with much less cutting involved. While simultaneously offering a better finish in an IB enclosure room where they might be regularly seen by the occupants. I doubt the strength of the material of the ribs is important provided they are deep enough and well cross braced. Shelf materials vary widely in cost. As do kitchen work surfaces if it was desired to use those for the ribs and shelves in a habitable room.
Where only a pair of really strong ribs were needed each side of a vertical array the ribs could be doubled up. The wall studs on either side of the vertical array would be sandwiched by two ribs attached to the same wall stud. Then the open ends between the doubled ribs could be closed off with a section of timber the same width as the wall studding. This construction should offer serious resistance to cyclic reaction leads.
The hollow double rib sections could even be sand loaded to increase the mass. (using sand in small plastic bags stuffed between the ribs) Or concrete paving slabs or other blocks built up on edge between the doubled ribs. Most wall studs are only 2" wide so the gap between the ribs is only 2" wide. Which rather limits the potential materials for mass loading. Make sure the floor can take the considerable localised load! Or greatly increase the area of the "foot" below the ribs with large and very thick plywood pads. The 2" gap could even be stuffed with MDF "planks" to further increase the stiffness and mass of the doubled ribs. The MDF stuffing would be screwed to the ribs to ensure they contribute to mass and stiffness.
Those building a false wall from scratch could arrange the ribs to extended backwards into the enclosure or forwards of the wall into the HT. Or even in both directions.
The ribs and shelves could even be made into a feature in the HT/ music room to carry books or a collection of CDs and DVDs or records. Books and records would both provide excellent mass loading of the wall around the array. CDs and DVD are too light to add much mass of their own.
All we need now is an experimental guinea pig (or IB lab rat) who wants to build a vertical array into a flimsy stud wall. Please form an orderly queue. ;D
Girder bridges have been around for quite a while. They rely on great depth in the side girders to resist the applied vertical loads loads on the roadway between the built up side panels. They take heavy and widely varying loads and absorb lots of serious vibration. Deep vertical side ribs and cross bracing shelves should do the same job in an IB baffle wall housing a vertical array.
Glue-lam and built up joists function well in many buildings. The depth of the joist is where the strength lies. This can be imitated for our IB purposes with deep plywood ribs set on edge to the applied loads and well attached to the existing vertical wall studs. The baffle will close the box at the front becoming the deck in our vertical IB "bridge". Stiffening shelves between the ribs will resist any twisting of the vertical ribs themselves under heavy reaction loads.
The ribs ought to be at least a foot deep from front to back and the full height of the room. The ribs must be well attached to the vertical wall studs, the floor (and hopefully) the ceiling.
I could even imagine an entire wall between two habitable rooms being stiffened with these deep ribs and the cross brace shelves being utilised for open storage. MDF might be just as useful as plywood in this context depending on the cost of each material locally.
Wide decorative chipboard and MDF shelves are readily available and could be utilised for the ribs and shelves with much less cutting involved. While simultaneously offering a better finish in an IB enclosure room where they might be regularly seen by the occupants. I doubt the strength of the material of the ribs is important provided they are deep enough and well cross braced. Shelf materials vary widely in cost. As do kitchen work surfaces if it was desired to use those for the ribs and shelves in a habitable room.
Where only a pair of really strong ribs were needed each side of a vertical array the ribs could be doubled up. The wall studs on either side of the vertical array would be sandwiched by two ribs attached to the same wall stud. Then the open ends between the doubled ribs could be closed off with a section of timber the same width as the wall studding. This construction should offer serious resistance to cyclic reaction leads.
The hollow double rib sections could even be sand loaded to increase the mass. (using sand in small plastic bags stuffed between the ribs) Or concrete paving slabs or other blocks built up on edge between the doubled ribs. Most wall studs are only 2" wide so the gap between the ribs is only 2" wide. Which rather limits the potential materials for mass loading. Make sure the floor can take the considerable localised load! Or greatly increase the area of the "foot" below the ribs with large and very thick plywood pads. The 2" gap could even be stuffed with MDF "planks" to further increase the stiffness and mass of the doubled ribs. The MDF stuffing would be screwed to the ribs to ensure they contribute to mass and stiffness.
Those building a false wall from scratch could arrange the ribs to extended backwards into the enclosure or forwards of the wall into the HT. Or even in both directions.
The ribs and shelves could even be made into a feature in the HT/ music room to carry books or a collection of CDs and DVDs or records. Books and records would both provide excellent mass loading of the wall around the array. CDs and DVD are too light to add much mass of their own.
All we need now is an experimental guinea pig (or IB lab rat) who wants to build a vertical array into a flimsy stud wall. Please form an orderly queue. ;D
