Discussion Are window sills normally framed with hard wood?

[Synomenon]

Ok, not sure if I'm using the correct terms.

I have these two small windows. They're around 16" x 16".






The little ledge or sills in front of each window. The ledge or sill is around 4.5" deep:





beneath that paint or drywall on the surface of those ledges / sills, is there normally a hard wood frame?

I need to screw a small shelf into each one using GRK cabinet screws.

So basically each window will have a small shelf sticking out like little planks. The wood shelves are 15" long x 15" wide. The ledge / sill will serve as a surface for each wood shelf to partially sit on and be screwed into.

 

[Micrornd]

Yes, they are normally framed in wood. FYI, normally in softwood (pine fir, larch, etc.) not hardwood (oak, cypress, walnut, etc.)

 

[Synomenon]

Would it be safe to screw each shelf down into this wood using GRK cabinet screws with washers?

 

[Micrornd]

It "should" be. It all depends on how much weight you put on the shelf and/or how far out on the cantilevered part you place the weight.
As long as you don't put so much weight on the cantilevered part that you pull the screws out (lever effect), you should be fine.

 

[Synomenon]

It's not too much weight going onto it.




So that thick shelf is going to be replaced by a longer shelf that has "legs" that will end up laying on the sills. This new shelf is probably 1 /3 the thickness but will span from the outer side of one window to the other.




I'm going to have that powered AM antenna, a powered FM antenna, HD radio tuner and that Echo Show 5 on it. All together ~ 5lbs. on the shelf.

The new shelf will also block the sunlight (coming from these windows) that somehow washes out the picture on the TV. I'll finally be able to remove those pillows.

 

[pcgeek11]

Yes, that should work just fine.

You could also get some curtains for those windows to block the light.

 

[Synomenon]

I hate curtains. Maybe remote controlled shutters or blinds. This shelf is much cheaper though.

 

[Greenman]

Would it be safe to screw each shelf down into this wood using GRK cabinet screws with washers?

Use quality plywood for the shelf and 3" screws to anchor it. You're probably going to have to put a piece of trim across the bottom of the shelf as the load on it will make the corner bead shift and crack.

 

[Synomenon]

The shelf is plywood. I was planning on using at least two of these on each side that will be resting on a sill:

GRK Fasteners 5/16 in. x 4 in. RSS Star Drive Washer Head Alternative Lag Screw 96005 - The Home Depot

The GRK Fasteners RSS screw is made from Climatek coated and hardened steel. Its sharp threads and point bite instantly into material (including hardwood), reducing the splitting effect caused by smaller

www.homedepot.com

Or

GRK Fasteners 5/16 in. x 5 -1/8 in. RSS Star Drive Washer Head Alternative Lag Screw 96010 - The Home Depot

The GRK Fasteners RSS screw is made from Climatek coated and hardened steel. Its sharp threads and point bite instantly into material (including hardwood), reducing the splitting effect caused by smaller

www.homedepot.com

Haven't decided whether I need 4" or 5". Will be using larger washers too.

 

[Mr.IncrediblyBored]

The framing is normally right underneath the drywall/plaster. Take a stud finder to the wall under the window to find the rough sill plate. A 3" screw is plenty, probably overkill, tbh.

 

[Greenman]

The shelf is plywood. I was planning on using at least two of these on each side that will be resting on a sill:

GRK Fasteners 5/16 in. x 4 in. RSS Star Drive Washer Head Alternative Lag Screw 96005 - The Home Depot

The GRK Fasteners RSS screw is made from Climatek coated and hardened steel. Its sharp threads and point bite instantly into material (including hardwood), reducing the splitting effect caused by smaller

www.homedepot.com

Or

GRK Fasteners 5/16 in. x 5 -1/8 in. RSS Star Drive Washer Head Alternative Lag Screw 96010 - The Home Depot

The GRK Fasteners RSS screw is made from Climatek coated and hardened steel. Its sharp threads and point bite instantly into material (including hardwood), reducing the splitting effect caused by smaller

www.homedepot.com

Haven't decided whether I need 4" or 5". Will be using larger washers too.

Depends on if they used a double sill or not. On a small window with a stucco exterior, I wouldn't expect it.

 

[Synomenon]

The shelf is in. I ended up using 3-1/8", #8 GRK screws with washer heads. I used five on each side. I then used one of these under the center of the shelf.