BEFORE THE ARCHITECT – CUSTOM HOME DESIGNING BACKGROUND – HOUSE DESIGN ARTICLES

GRAB BARS  BATHROOM SAFETY WALL DESIGN

IN ELEVATION AND IN PLAN VIEW

By Before The Architect  Copyright 2009

YOU MAY FREELY QUOTE THE AG WITH PROPER ATTRIBUTION

GRAB BAR WALL DESIGN, SECTION DETAIL IN ELEVATION AND IN PLAN VIEW

INTRODUCTION TO BATHROOM SAFETY WALL DESIGN USING GRAB BARS

Comment:  While the section detail in elevation and in plan view at the bottom of this webpage can put to rest most design detail inquiry, AG adds to it considerable text up-front to minimize misunderstanding in both matters of design and construction.
 

1)   The wall design structure interiors to an adaptable bathroom, for bathroom safety's sake . . .

a)     shall be not load-bearing and

b)     shall be not plumbed and

c)      shall be not wired except as required by code and then, if at all possible, limited to single-bay pulls
 

Comment:  Any interior wall design to an adaptable bathroom should remain fair game for resiting or complete removal in order to free-up or reuse space interiors.  Freedom from load bearing, and electrical cables, and plumbing pipes significantly facilitates wall amendment.

Comment:  The interior walls upon which we focus for wall design shall include, among others, water closet interior walls that may need to be removed for easier access to the plumbing fixture, closet wall interiors to an adaptable bathroom that may eventually prove too difficult to negotiate for access or their obstruction of floor space, etc.  Amending load-bearing partitions, recoursing plumbing and recoursing  electrical wiring can be major projects each of itself.  It is this Standard that prompted the floor and wall tiling standards of complete coverage before interior walls are applied. 
 

2)     Wall design structure shall be braced for attached grab bars to successfully withstand force of not less than 350 pounds in any direction 
 

Comment:  In some support situations – for example, accidental fall, panicked support, body weight levered up to 3 linear feet out and away from wall attachment when using swing-away bars, etc. – necessary and sufficient attachment must exceed otherwise regulated standards (of 250 pounds, pull only).

Comment:  Some suggest bracing walls for grab bar attachment of grab bar using plywood sheathing either in lieu of wallboard interiors finish clad or underneath a wallboard interiors finish clad.  Forget about it.  Still others suggest that you can get lucky enough to hit a wall stud on center every time you need to fasten a grab bar.  Forget about it, too.  We regard generally recognized standards in this area to be insufficient both as to withstandable weight and force vector.  Subsequent standards should prove indicative of better ways and means. 
 

3)     Closet hanging bars and towel bars and the like shall not be considered grab bars 
 

Comment:  Grab bars are grab bars.

Comment:  Looking like a duck is only one qualification.  If you insist on making a towel bar or hanging bar a grab bar, give it up.  Grab bars are for grabbing, not adorning 
 

4)     Wall structure design shall be braced for an attached grab bar in not less than the following areas

a)     behind toilets and bidets: In width on either side of a front-to-back centerline the greater of the sidewall corner and 24 linear inches and in height from not greater than 18 linear inches over finished floor level to not less than 40 linear inches over finished floor level

b)     beside toilets and bidets (where not less than one sidewall shall be proximate at 18 linear inches from the front-to-back centerline of any given fixture): In width forward from the back wall to greater of endwall or 5 linear feet and in height from not greater than 18 linear inches over finished floor level to not less than 40 linear inches over finished floor level

c)      in bathtubs: in width to the entirety of side walls and back walls and in height from tub deck edge to no less than 40 linear inches over finished floor level

d)     in showers: In width to the entirety of walls not plumbed and in height from not greater than 18 linear inches over tub floor level to not less than 40 linear inches over tub floor level

e)    elsewhere, as in handrails: in width (, or length) as needed and in height at centerline of attachment not less than ±5 linear inches 
 

Comment:  These dimensioned areas are in excess of regulatory specifications in order to extend application adaptability and secure attachments substantially inside of structured edges.

Comment:  Some grab bars, particularly swing-away bars, can be set lower than conventional heights over floor level.  The standards’ bracing areas are meant to offer the widest reasonable opportunity to adapt to spectral conditions.  Attachments to structure at its edges at bottom, sides, or top may fail for splitting out from insufficient mass on one side of a fastener.
 

5)     Wall design structure braced for an attached grab bar with materials and methods

a)     shall use mechanical fasteners such as nails, screws, bolts, and metal plate connectors as by Simpson Strong-tie and

b)     mechanical fasteners shall be applied in not less than 2 directions faced or toed or both and

c)      shall be continuous across the braced area except as required to let plumbing materials

d)     shall be braced in not less than 2 directions interior to the wall wherever possible, i.e., wall to crossing wall, wall to floor
 

Comment:  Specify mechanical as opposed to chemical fasteners because the mechanical fasteners are not only necessary and can be sufficient, but also they are substantially diminished in potential toxicity.  Multidirectional, multimember fastening enhances attachment.

Comment: Forces with which to be reckoned for grab bars can come from any direction, principally characterized as shear force and vectored as horizontal and vertical for purposes of fastening.

Comment: Note that lets for plumbing fixtures means both structural sides of the let must be firm, i.e., only the let bay is not structured.

Comment:  Note that floor-braced grab bars shall not create an obstruction of themselves.

6)     A suggested application for grab bar bracing of a wall could consist of

a)     Either

i)       linear inches x solid lumber 

ii)    not finger-jointed, scabbed, split, or otherwise discontinuous and

iii)  full studs at 12 linear inches or 16 linear inches on center– singled or doubled and

iv)   with solid, full-depth blocking 1 or 2 layers deep and

v)     if 1 layer of blocking or if there is extra depth to the applied wall, then full-length stud wood backing to wall studs at 90°, or right angles, to the wall studs, flush to the wall studs (as in an “L” shape in plan view cross-section) and then

vi)    fastened to the wall abutted wall stud and the solid blocking with not less than 10d galvanized common or deformed nails face-nailed (note: toe-nailing shall not be a means of permanent fastening) or with Simpson Strong-Tie hangers

vii) See illustration below 
 

Stud Wall Reinforcement for Adaptability, Section in Plan View and in Elevation

Key to abbreviations:  ADH=ADHesive; AP=Application; BET=BETween; BT=BaTh; CL=CenterLine; DBL=DouBLe; FFL=Finish FLL; FLL=FLoor Level; H=Height; INT=INTerior; MIN=MINimum; NL=NaiL; OC=On Center; OFFL=Over FFL; RNF=ReiNForce; SHW=SHoWer; STRC=STRuCture; WL=WaLl
  

b)      or

i)        alternatively, in wall segments where the application suggested immediately above is inappropriate or inapplicable

ii)     a shear wall of not less than 1 linear inch thick plywood (face grain perpendicular to the stud lines, 2 layers of ½ linear inches sheets may suffice if continuously glued) may be used

iii)   fastened with not less than 10d galvanized common or deformed nails face-nailed to each structural member as follows:  not greater than 6 linear inches on center in the field, not greater than 4 linear inches on vertical edges, not less than double-nailed on the horizontal edges
 

Comment: Note that Before The Architect prefers the “L”-shaped application for its opportunity to structure and fasten multidirectionally over substantial surface areas.
 

7)      Rail and grab bar dimensions shall respect ADA/ADAAG

a)      including thresholds (a/k/a saddles, transitions)

b)      wall outset specifications

c)       clearances for floor-loaded fixtures and

d)      under lavatory counters

e)      electric light switch control siting and

f)        plumbing water flow controls and

g)      in all other matters not directly addressed herein under shall respect ADA Guidelines
 

Comment:  There is a lot of worthy, definitive information in already published rules and regulations that is worthy.

Comment:  Not everything is worthy, definitive information in already published rules and regulations.  We’ve seen this already, and there’s more to come.

8)     Soap dish handles and holders, shelving, and other potential protrusions interior to a shower or bathtub wall plane shall be prohibited, except that these shall be permitted to protrude — grab bars, water supply and drainage devices, controls, holders, and escutcheons albethey to protrude to the minimum
 

Comment:  Removable and avoidable physical hazards should be removed and avoided.

Comment:  Some shower and bathtub physical hazards can be removed, or avoided, but not all.  That is, not until bathroom technologies advance some.  This standard can impose a planning burden to let wall bracing for intrusions while maintaining structural integrity to the remaining wall.

Note that devices, controls, escutcheons, fixtures, cabinets, counters, backsplashes, tiles, and trim joints shall be sealed to water intrusion.

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