[tarnishd]

Hi All,

I'm moving into my first house soon and the first project on the list involves adding some support for the load bearing wall that was removed. The ceiling appears to be lath and plaster, with joists that are nailed together (huh?). The joists span from one end of the house across the width, about 6m (20') in total. I'm just guessing but it looks like the joists were nailed where the load bearing wall used to be. So needless to say there are signs of a minor sag in the ceiling.

The home inspector said to "hang a beam" in the attic and secure the joists to it, since it is only the ceiling weight being supported I will be using 2 laminated 2x10s across the span of two existing walls that are directly over the I-Beam in the basement.

The approach I think will work best is cutting a hole in the ceiling, feeding up the beam into the attic.

Here is a shot of the joists nailed together,

Any advice or comments would be awesome, here is what I'm going to do...

1. Jack up the ceiling in the area I plan to work by about 2.5-3cm (1") using some type of jack with 2x6s to spread the weight on the floor and ceiling.

2. Construct 2 temporary support walls about 1m (3') apart on both sides of the work area and hammering in the vertical 2x4s to provide some extra stiffness before toenailing them in so they don't slip.

3. Place the two 2x6s across the joists, securing them on the joists that are directly over the existing walls (or build up the wall header if the joist aren't directly overtop of the wall and attach to that)

4. Attach the joists to the 2x6s using hurricane ties with some good screws

5. Remove the support walls.

6. Slowly release the jack.

I have a couple questions.

Can I safely cut the hole through the lath and plaster without a lot of repair? I will likely put some plaster washers around the area I cut and do some serious scoring of the plaster with a utility knife first.

Is this the best way to get the beams up in the attic? The beam will be about 3m (10').

Can I walk on the joists after I have the support walls built to get across to the other end where the beam will go? The joists currently will not support my weight.

Is this going to be a killer project that I should just avoid by putting in an external header, or a flush header?

Thanks in advance. My ability to get more accurate measurements and pictures is zero until I actually move into the place. I took a week off of work to try and get this, among a few other things done right away when we get possession of the house.

-T

 

[oh'mike]

What you are describing sounds like a pretty good plan--

No jack will be needed---you can do the lifting of the ceiling with the studs for your temporary wall----toe nail them into the temporary top plate and hammer them in at the bottom---I think you can get about 1/4 inch of lift per stud--so you may use several as you go for the 1" of lift---


A multi tool with a carbide blade has always worked well for cutting old plaster---then a wood blade for the old wood lath---

 

[TheCamper]

I am not sure I understand what you are proposing to do, but I think you are looking to use two 9 1/2" LVLs (or 2 X6s, I am not clear on this part) to span the distance where a bearing partition was removed; the LVLs will be in the attic above the existing ceiling joists with each end of the LVLs bearing on partitions that take the load down to the girder in the basement; and you will use hurricane ties to attach the joists to the LVL effectively hanging the joist from the LVL using screws.

Generally screws do not resist shear forces as well as nails, and the hurricane ties are not designed to act as joist hangers.

You would benefit from an architect or engineer specifying a fix, you will know it is adequate and haveing the sealed and signed plan will resolve any questions when the next home inspector inspects when you sell the house. If you are set against the design professional, consider oversizing the LVLs, installing them as a flush header, use joist hangers with the specified fasteners, post down the ends of the LVL, and block to the girder. good luck.

 

[Duckweather]

I think there are other hangers to do what you need. Check a Simson or other hanger book. If you loosen any plaster prop it up and remove insulation so you can get to the lath. Where it squeezes through usually crumbles. Mix Durabond with latex additive so you can pour an inch or so layer over the lath to bond it to the plaster. The more additive the stickier it gets. You can patch holes with it too but it is too sticky to trowel smooth. It will need a coat of joint compound to finish

 

[tony.g]

Generally screws do not resist shear forces as well as nails

That might be debateable, but in this instance, nailing might cause more damage to the old plasterwork.
It's only a ceiling and the load per connection won't be that much.

 

[tarnishd]

Sounding good...

I am not sure I understand what you are proposing to do, but I think you are looking to use two 9 1/2" LVLs (or 2 X6s, I am not clear on this part) to span the distance where a bearing partition was removed; the LVLs will be in the attic above the existing ceiling joists with each end of the LVLs bearing on partitions that take the load down to the girder in the basement; and you will use hurricane ties to attach the joists to the LVL effectively hanging the joist from the LVL using screws.

This is exactly what I plan. Though an LVL seems like it is a manufactured beam, I just plan to glue together two 2x10 pieces of lumber and add some screws.

No jack will be needed---you can do the lifting of the ceiling with the studs for your temporary wall----toe nail them into the temporary top plate and hammer them in at the bottom---I think you can get about 1/4 inch of lift per stud--so you may use several as you go for the 1" of lift---


A multi tool with a carbide blade has always worked well for cutting old plaster---then a wood blade for the old wood lath---

Awesome tips! Thank you

I think there are other hangers to do what you need. Check a Simson or other hanger book. If you loosen any plaster prop it up and remove insulation so you can get to the lath. Where it squeezes through usually crumbles. Mix Durabond with latex additive so you can pour an inch or so layer over the lath to bond it to the plaster. The more additive the stickier it gets.

I'm pretty sure I will probably loosen some plaster doing this so great advice. I'll take a look into some other hangers to see if something is more appropriate. I chose the hurricane ties based on some websites like Lowes and HomeDepot saying in the description of hurricane ties: "Use also for general tie purposes, strongback attachments and as all-purpose tie where one member crosses another."

I believe what I'm proposing is to use a strongback to hold up the joists.

That might be debateable, but in this instance, nailing might cause more damage to the old plasterwork.
It's only a ceiling and the load per connection won't be that much.

My biggest fear is vibrations bringing down the whole ceiling.


So any thoughts on walking on the joists after the temporary walls are erected?

Thanks for the great info so far,
-T

 

[hand drive]

if you are hanging the joists from the beam placed above them use 4 2xs to make the beam. Because of the 6" beam spread it will give lateral tipping strength. Also consider strong blocking at the walls the beam sits on and possible collar/rafter ties of sorts mid span that counter appose each other and butt into the edges of the beam to help from tipping. The type of joist strapping that is used for cgi floor systems is what you will need for the hangers. hanging stuff from beams is not really the way we usually do that type of support anymore so finding the straps may be difficult.

Also, you do not need two temp walls, just one under the joist splices and yes you can walk up there once the temp wall is in place...

 

[tarnishd]

You would benefit from an architect or engineer specifying a fix, you will know it is adequate and haveing the sealed and signed plan will resolve any questions when the next home inspector inspects when you sell the house. If you are set against the design professional, consider oversizing the LVLs, installing them as a flush header, use joist hangers with the specified fasteners, post down the ends of the LVL, and block to the girder. good luck.

I'm not totally against it to be honest. In about 10 years we are planning to add a second story to the house so this is really meant to stop the ceiling from sagging further or falling down until we add the second floor which will require a lot more support everywhere. I just figured it would be overkill for now.

 

[tarnishd]

hanging stuff from beams is not really the way we usually do that type of support anymore so finding the straps may be difficult.

Thanks for the tip about the one support wall, it makes sense.

What is usually done now instead of hanging beams?

 

[hand drive]

Thanks for the tip about the one support wall, it makes sense.

What is usually done now instead of hanging beams?

Glad to help. now the beam is either flush mount or dropped. Flush mount for your situation would need evaluation because of the joist splice. The spliced joists help hold the rafters and ridge up and keep the walls from spreading. If you cut those for a flush mount beam rafter collar ties will be needed to keep the rafters and ridge from sinking. A dropped beam could go under the ceiling in the room but you probably do not want that...

 

[GBrackins]

Glad to help. now the beam is either flush mount or dropped. Flush mount for your situation would need evaluation because of the joist splice. The spliced joists help hold the rafters and ridge up and keep the walls from spreading. If you cut those for a flush mount beam rafter collar ties will be needed to keep the rafters and ridge from sinking. A dropped beam could go under the ceiling in the room but you probably do not want that...

typically when we install a flush beam with hangers for the joists we also install a strap tie that connects opposing joists in the case of an attic. If it were for the second floor we create a tension tie using wood structural panel sheathing that spans over the beam-to-joist connection. You need to ensure that the joists do not pull away from the beam.

Hangers have limited resistance to lateral loads.

 

[Duckweather]

If you really need to beef up the durabond you can add horsehair to it, but you have to use fiberglass hair, (from fiberglass horses?) or a body shop.

 

[tony.g]

if you are hanging the joists from the beam placed above them use 4 2xs to make the beam. Because of the 6" beam spread it will give lateral tipping strength. Also consider strong blocking at the walls the beam sits on and possible collar/rafter ties of sorts mid span that counter appose each other and butt into the edges of the beam to help from tipping. The type of joist strapping that is used for cgi floor systems is what you will need for the hangers. hanging stuff from beams is not really the way we usually do that type of support anymore so finding the straps may

I agree that he would only need one wall as temporary support.
But would he really need four 2xs and additional blocking? If his span is only 20ft, and the beam is only 10ft long, he is only supporting about 100 sq ft of ceiling, which is no great load.
Also, a couple of the Simpson hangers to each connecion would be fine, again bearing in mind the low load at each connection. Many old houes like this have the ceiling supported mid-span by a few thin timber hangers casually naie to the ridge, and they stay up.
We need to remember that the ceiling has been in its present condition for some time without collapsing, and that he only want this as a temporary fix.
Sure, it's good to see a job well done and to know it will last indefinitely, but a balance has to be struck. In short, if it stands up now, it can only be better when he's done the job.

 

[hand drive]

typically when we install a flush beam with hangers for the joists we also install a strap tie that connects opposing joists in the case of an attic. If it were for the second floor we create a tension tie using wood structural panel sheathing that spans over the beam-to-joist connection. You need to ensure that the joists do not pull away from the beam.

Hangers have limited resistance to lateral loads.

I have dealt with bizarre engineering involving tall width beams and the crazy things on paper to try and put in the air and hold stuff up .... Anyway, most of the time some beams were/are 18" and the joist were /are 2x8 etc so really the only flush intersecting point is underneath the beam along the bottom.

if you are hanging the joists from the beam placed above them use 4 2xs to make the beam. Because of the 6" beam spread it will give lateral tipping strength. Also consider strong blocking at the walls the beam sits on and possible collar/rafter ties of sorts mid span that counter appose each other and butt into the edges of the beam to help from tipping. The type of joist strapping that is used for cgi floor systems is what you will need for the hangers. hanging stuff from beams is not really the way we usually do that type of support anymore so finding the straps may

I agree that he would only need one wall as temporary support.
But would he really need four 2xs and additional blocking? If his span is only 20ft, and the beam is only 10ft long, he is only supporting about 100 sq ft of ceiling, which is no great load.
Also, a couple of the Simpson hangers to each connecion would be fine, again bearing in mind the low load at each connection. Many old houes like this have the ceiling supported mid-span by a few thin timber hangers casually naie to the ridge, and they stay up.
We need to remember that the ceiling has been in its present condition for some time without collapsing, and that he only want this as a temporary fix.
Sure, it's good to see a job well done and to know it will last indefinitely, but a balance has to be struck. In short, if it stands up now, it can only be better when he's done the job.

The multiple beam option depends on how it will be built and the hangers used that are hanging the joists off of the beam. The home owner mentioned that he can not walk on the ceiling with it collapsing so it is not considered a temp fix.

 

[abjkkc]

I am by no means an expert, but going through a pretty similar situation as you. You can see my thread over at:
http://www.diychatroom.com/f19/load-bearing-wall-removal-157227/

My situation is compounded by the fact that I'm not putting my beam over the joist splice, but otherwise very similar. My house width is 25', while yours is 20', my beam length is 11', while yours is 10'. I went to the local Lumber yard and they sized an LVL beam of 2 - 9 1/2" LVL's, 11' long. He said that if I didn't want to use LVL, I'd have to use 3 - 2 x 12's, so be careful about your beam size. If you have a Lumber yard close, use them! The guys who post regularly here know their stuff, and while they won't size the beam for you, their advice about getting a professional to help in sizing the beam is right on. Like you, the only thing above my joists is insulation and a roof, but this is still a really big deal.

I'm planning on using Simpson THA-218 hangers on mine (this is what was recommended by the lumber yard). You can see them here (http://www.strongtie.com/products/connectors/tha-thac.asp), although if you're going directly over the splice, you may need the THA-218-2 (don't get the THA-418 - the joist hanger width is 3 5/8" which is for supporing an LVL. The 218-2 is 3 1/8" wide, so 2 - 2x joists will fit in it perfectly.
You'll have to cut holes in the ceiling to pass the hangers up through so the joist fits in the saddle.

Like I said, I'm certainly no expert, but my project has been approved by the local building inspector, and I just though my situation might help.

Good Luck!

 

[tarnishd]

I am by no means an expert, but going through a pretty similar situation as you. You can see my thread over at:
http://www.diychatroom.com/f19/load-bearing-wall-removal-157227/

My situation is compounded by the fact that I'm not putting my beam over the joist splice, but otherwise very similar. My house width is 25', while yours is 20', my beam length is 11', while yours is 10'. I went to the local Lumber yard and they sized an LVL beam of 2 - 9 1/2" LVL's, 11' long. He said that if I didn't want to use LVL, I'd have to use 3 - 2 x 12's, so be careful about your beam size. If you have a Lumber yard close, use them! The guys who post regularly here know their stuff, and while they won't size the beam for you, their advice about getting a professional to help in sizing the beam is right on. Like you, the only thing above my joists is insulation and a roof, but this is still a really big deal.

I'm planning on using Simpson THA-218 hangers on mine (this is what was recommended by the lumber yard). You can see them here (http://www.strongtie.com/products/connectors/tha-thac.asp), although if you're going directly over the splice, you may need the THA-218-2 (don't get the THA-418 - the joist hanger width is 3 5/8" which is for supporing an LVL. The 218-2 is 3 1/8" wide, so 2 - 2x joists will fit in it perfectly.
You'll have to cut holes in the ceiling to pass the hangers up through so the joist fits in the saddle.

Like I said, I'm certainly no expert, but my project has been approved by the local building inspector, and I just though my situation might help.

Good Luck!

Great info - there is a lumber yard near by, I'll go and have a chat with them and see what they have to say.

My only fear with using the joist hangers that you mentioned is that I would have to cut the lath at each joist. The lath runs at 90 to the joists so this would leave these few strips of lath completely unsecured from the joists. Not sure if it matters, it may hold with just the plaster securing it but it makes me nervous.

The only experience I have with lath/plaster is knocking down a ceiling to help my parents with their renovation and I seem to remember kicking down from behind would cause a HUGE portion to fall.

I took a brief look at your thread and it looks like a lot of good info - I'll have a read through it tonight.

Thanks
-T

 

[tony.g]

tarnishd; here are some figures for you to put the beam size in perspective.

If your beam is spanning 10ft, and the width of the room is 20ft, then about 100 sq ft of ceiling will be supported by the beam.
We then need to work out the total load the beam will be carrying and this is split into two components - dead load and live load.
The DEAD load is the weight of the structure itelf; typically, the dead load of a ceiling is around 10 psf. The LIVE load is the weight of things you might store in the loft space. Your local code will specify this but it should be around 20 psf.
Therefore the total load your beam will carry will be 100 x (10+20) = 3000 lb (excluding the weight of the beam itself).
Knowing the total load, the span, and the cross-sectional size of the beam, it is possible to work out the maximum bending stress in the timber. Without going into the figures here, the maximum stress in your beam will be just shy of 1000 lb/sq.in.
I would say that is borderline for mot commonly-available timbers, so I would consider upgrading to three 2x10s to be on the safe side.

(if you are not bothered about a permit, you wouldn't need to take account of any live load and the two 2xs would do).

 

[GBrackins]

this link will provide you with the Prescriptive Girder and Header Spans based upon the 2009 International Residential Code.

 

[tarnishd]

this link will provide you with the Prescriptive Girder and Header Spans based upon the 2009 International Residential Code.

Wow that's a great resource! So supposing my 20ft house width, ~10ft span it looks like

3-2×10 with one jack post

I just noticed this is for an exterior bearing wall... so for an interior bearing wall it would actually be,

4-2×10 with one jack post

but this is for supporting 1 floor. Is the attic considered a floor?

 

[GBrackins]

do you have a scuttle (small opening), pull down stairs or fixed stairs to access your attic?

scuttle and pull down stairs the code requires 20 pounds per square foot live load (as tonyg said 10 psf dead load typical)

if fixed stairs then 30 psf live load