Removing part of the wall next to the door

[hardbutmild]

I have little experience with existing structures and what can or should be done in some situations so I'd like your opinions.

There's a wall in a structure and an architect plans to remove part of it right next to the door to widen the door. I don't know the exact situation since I'll go to look it up in a few days, but I'd like to be prepared since I usually deal with new structures.

The existing door has a beam above it, but if the door is widened the beam will loose support. At what point do you think it should worry me?
My logic is that if if the door is not close to the edge, a new beam is not necessarily needed since the blocks on the left and right can take the diagonal load.

But if the opening is close to the edge, this can not work without the horizontal tie and new beam is needed above the door.

Does this sound ok to you or should I always insist on putting in the new beam?

EDIT: Of course, the distance from the top of the opening to the slab is also important. I drew a picture of what I think can bear vertical loads.

 

[SteelPE]

My standard practice is to always put lintels above an opening in masonry walls. In any situation you will need to support the weight of the "triangular" material above the opening.... and in order for arching to occur, you must be able to resist the thrust from the arch on the adjacent sections of wall.

Also remember, the original designer believed support was required by evidence of the installed beam, why would you think it isn't required?

 

[hardbutmild]

Thank you for your advice. I agree with you completely. I guess I'm just trying to see how others handle this situation in hope to hear that the lintel is needed. I wasn't sure what other peoples experiences are and I don't have much experience myself in this matter so I figured it's better to ask.

 

[Ron247]

Put in a new beam. Even if it was to stay in place while you make your modifications, someone in the future may remove just the door and wind up with a head full of old beam and block.

 

[MIStructE_IRE]

Yep, new lintel/beam for me also. You’d want to be very brave to rely on the arching effect of existing masonry alone, and even if you did, what supports the triangle of masonry other than mortar’s tensile resistance? No way!

 

[hardbutmild]

Thanks everyone, this helps a lot. I agree but wanted you all to confirm it.

There's a lot of URM where I live so a lot of buildings have been standing for a century now without lintels, that's why some architects and home owners insist that it's not necessary... however I agree that it's much much better to put it in and will do so.

Thanks to all of you once again!

 

[phamENG]

I agree with those above who recommend the lintel. I've heard that from contractors before (we don't need it..it stays up on its own...). This is my typical response:

Even if you have arching action over the opening to carry floor or roof loads from above, what holds up the masonry under the theoretical arch? If you don't have a lintel, the only answer is tension in the mortar. Mortar certainly has tension capacity, but it's easily degraded by rain and other environmental factors. If the architect, contractor, or owner are willing to place the safety of people using the door on the condition of the paint above the door, the project team risk tolerance is a bit too high for my taste. I used to have some pictures of openings where the masonry under the 'arch' had fallen out. Sadly I didn't take them with me when I left a previous employer.

 

[BAretired]

Good decision!!

BA

 

[Ron247]

I went to a new construction once that was a center 2-story brick with a single story wing on each side (master bedroom & living room). The brick has been up about 2 weeks. All the brick over the master bedroom roof collapsed that morning and about 26'x14' of brick fell onto the master bedroom floor right where the bed would have been. After arguing with the contractor about how brick will not arch like he thinks and determining what to do to correct the mess, I said "lets go to the living room next". He then argued about correcting the living room since it had not collapsed. I asked him if he built it the same as the master since it was a mirror image house. He said yeah, but it is ok. I told him yesterday both were ok by his definition.

 

[BAretired]

That is pretty scary!

BA