DIY Home Improvement Forum banner
1 - 15 of 15 Posts

· Registered
Joined
·
112 Posts
Discussion Starter · #1 ·
Hope you people can advise me here. She needs more counter space, we have a story and a half wood construction 1950's home. The house sits three course of cement block high, off ground level. I'm considering bumping out an outside wall, the depth of a kitchen cabinet base, and seven feet wide. But I don't want to add foundation, just cantilever construction. If my floor joice ran the other way I'd be pretty confident doing this. But they run at right angle to what I think the floor, on the bump should be. What do you all say ?

Thanks
 

· Retired Moderator
Joined
·
25,780 Posts
Hire an architect or designer to draw up plans---you will be glad you did---you need a permit for that type of work in most places--so plans are needed to get one----

Even if permits are not needed---building this correctly must be done ---you could end up with a financial disaster if done wrong---

Any thing can be done---but I think you may find that a proper concrete footing is best and cheapest---Mike----
 

· Registered
Joined
·
9,055 Posts
You can span that with LVL/4x12 and post/footing on 2 ends. Better insurance than cantilever and having to clear away the inside joists. I am not sure what you mean by right angle, but your cantilever may be extending out too much. My floor is 2x10 joists and when I wanted 24" cantilever, town inspector wanted engineer sign off.
 

· Registered
Joined
·
112 Posts
Discussion Starter · #5 ·
You can span that with LVL/4x12 and post/footing on 2 ends. Better insurance than cantilever and having to clear away the inside joists. I am not sure what you mean by right angle, but your cantilever may be extending out too much. My floor is 2x10 joists and when I wanted 24" cantilever, town inspector wanted engineer sign off.

In other words the floor supports run North and South, and the proposed bump out floor runs East and West. Now that I'm talking with you folks, I can see where the weight of the addition, might tend to pull the the upper plate out.
 

· Registered
Joined
·
9,055 Posts
You can't cantilever there without reframing the floor under you, which is recreating a girder and bringing out the joists. Even then you may have to use LVL joists to have 30" or more overhang.

Search for images of framing a cantilevered floor.

Is it a problem because you don't have enough setback in the property?
 

· Registered
Joined
·
112 Posts
Discussion Starter · #7 ·
You can't cantilever there without reframing the floor under you, which is recreating a girder and bringing out the joists. Even then you may have to use LVL joists to have 30" or more overhang.

Search for images of framing a cantilevered floor.

Is it a problem because you don't have enough setback in the property?
There is room, I was looking at a less expensive way of doing it, instead of pouring a footer and building a block foundation.

Thanks
 

· Registered
Joined
·
9,055 Posts
You don't need full foundation. I think you want to extend just 7' long by about enough for a wall and width of cabinets? You just need two 12" post with 18"x12" round footing, below your frost depth. Spanning the posts would be double 2x12 beam that you would attach the short joists and build a wall on. It is like building a deck, except you have more weight on the posts, accounting for cabinets, countertop, window, wall, roof, etc.

You will have a space beneath, but that can be covered with lattice, landscaping, etc.

Usually, post supports are cheaper than creating a cantilever, more labor.
 

· Registered
Joined
·
112 Posts
Discussion Starter · #9 ·
You don't need full foundation. I think you want to extend just 7' long by about enough for a wall and width of cabinets? You just need two 12" post with 18"x12" round footing, below your frost depth. Spanning the posts would be double 2x12 beam that you would attach the short joists and build a wall on. It is like building a deck, except you have more weight on the posts, accounting for cabinets, countertop, window, wall, roof, etc.

You will have a space beneath, but that can be covered with lattice, landscaping, etc.

Usually, post supports are cheaper than creating a cantilever, more labor.
Sounds good, just need to see what the city says.

Thanks
 

· Registered
Joined
·
28 Posts
The cheapest way is to mount a 7' beam on 2 piers or posts 2' from the house foundation. Place the floor joists on the beam and build upwards from there. The downside is that the area under the bump out is a hangout for animals, weeds and trash. Of course it will be exposed to the cold to. Expect to get some questionable looks when it is time to sell.

The premium way to build is to build a masonary/concrete foundation extending to below the frost line. When you go to sell your home, this method will show you went the extra mile and did quailty work.

As said earlier, check with your building department to see if they will allow the first method and what their specific requirements are.

Good Luck on making the wife happy
 

· AHH, SPANS!!!
Joined
·
1,751 Posts
a piece of fiber cement hardie panel can be used on the underside of the bumpout, or treated 1/2" plywood with the correct fasteners and lots of insulation. if done that is all the next person to buy the house will want to know,is it insulated and is there critters living up in there, lol
if you were to do a foundation it would most likely have to have a cutout in the original foundation for access to the bumpout crawlspace
 

· Registered
Joined
·
112 Posts
Discussion Starter · #15 ·
a piece of fiber cement hardie panel can be used on the underside of the bumpout, or treated 1/2" plywood with the correct fasteners and lots of insulation. if done that is all the next person to buy the house will want to know,is it insulated and is there critters living up in there, lol
if you were to do a foundation it would most likely have to have a cutout in the original foundation for access to the bumpout crawlspace
Thanks for the tip H D.
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top