I hope someone knowledgeable can help me with this. I have surfed around a bit on the forum without finding the information I need.
We are going to extend the house with an entrance porch. We've dug a hole and laid gravel, then we're going to cast a foundation and build a crawl space foundation.
The man I live with claims that we should NOT attach any reinforcement bars to the existing building, but let the extension stand "freely" beside it. This sounds completely insane to me, am I wrong???
He says we should not reinforce it together because the extension is not as deep down as the rest of the house (basement).
Grateful for answers so I can sleep more peacefully at night
We are going to extend the house with an entrance porch. We've dug a hole and laid gravel, then we're going to cast a foundation and build a crawl space foundation.
The man I live with claims that we should NOT attach any reinforcement bars to the existing building, but let the extension stand "freely" beside it. This sounds completely insane to me, am I wrong???
He says we should not reinforce it together because the extension is not as deep down as the rest of the house (basement).
Grateful for answers so I can sleep more peacefully at night
Your husband is absolutely right. It's best to avoid mixing new and old constructions if it can be avoided.
Firstly, the house has settled over several years. An extension does not settle in a shorter time. If the extension is merged with the house, you risk having the extension pull apart the old house at the connection point.
Secondly, the extension is separated from the existing house for the same reason with a so-called expansion joint, and only in areas (especially the roof connection) where it cannot be avoided to connect the extension with the existing house, a flexible joint is created. This is so the extension can move freely, independent of the existing building.
There are far too many extensions made that not only differ in the foundation level but are also cast together with the existing building, resulting in major settlement cracks as the final outcome. It makes no difference that attempts have been made with dowels in the seam (which only handle horizontal forces) and similar methods. The greatest danger with settlements does not lie in that direction. It's vertical.
If the extension is carefully made and free-standing/disconnected from the house, most of the settlements in the existing house are avoided. However, it is almost impossible to avoid minor cracks indoors. Therefore, a wooden strip in the transition between new and existing is good to have so it can easily be replaced after 5-10 years when the major settlements are resolved. (It is generally estimated that they are completely gone at 93% compression of the subsoil.)
______________________________
The Builder
Firstly, the house has settled over several years. An extension does not settle in a shorter time. If the extension is merged with the house, you risk having the extension pull apart the old house at the connection point.
Secondly, the extension is separated from the existing house for the same reason with a so-called expansion joint, and only in areas (especially the roof connection) where it cannot be avoided to connect the extension with the existing house, a flexible joint is created. This is so the extension can move freely, independent of the existing building.
There are far too many extensions made that not only differ in the foundation level but are also cast together with the existing building, resulting in major settlement cracks as the final outcome. It makes no difference that attempts have been made with dowels in the seam (which only handle horizontal forces) and similar methods. The greatest danger with settlements does not lie in that direction. It's vertical.
If the extension is carefully made and free-standing/disconnected from the house, most of the settlements in the existing house are avoided. However, it is almost impossible to avoid minor cracks indoors. Therefore, a wooden strip in the transition between new and existing is good to have so it can easily be replaced after 5-10 years when the major settlements are resolved. (It is generally estimated that they are completely gone at 93% compression of the subsoil.)
______________________________
The Builder